Sextant simulator-based ship positioning virtual training system

Abstract

The invention discloses a ship positioning virtual training system based on a sextant simulator. Comprising a 3D modeling reproduction module, a data setting module for setting virtual positioning practice data, a simulation scene construction module for setting a marine virtual training scene, an interactive training module and a positioning model construction module for acquiring an astronomical positioning model and a landmark positioning model. And the comprehensive evaluation storage module is used for acquiring result data and operation grade scores of each operation training stage, and obtaining a virtual training result of ship navigation positioning according to the constructed astronomical positioning model or landmark positioning model based on the result data of each operation training stage. The method solves the problems that traditional manipulation training generally depends on actual ship training, but has certain limitation and problems, due to the reasons that actual ship training is high in cost and high in safety risk, complex navigation environments cannot be truly represented and the like, diversified and flexible operation training scenes are difficult to provide, and the training efficiency is high. And sailors cannot effectively understand and master ship positioning principles, skills and experiences in various complex navigation environments.

Description

Technical Field

[0001] The invention relates to the technical field of navigation and positioning of marine vessels, and in particular to a virtual training system for ship positioning based on a sextant simulator. Background Art

[0002] High-precision ship navigation and positioning helps the on-duty driver to always understand the navigation environment of the ship and supervise the execution of the route. With the development of modern science and technology, navigation technologies such as GPS provide support for navigation and positioning of sailing ships.

[0003] However, in the absence of electronic systems, satellite signals and other equipment, or inadequate management and maintenance of some equipment, or in complex electromagnetic environments, it is impossible to accurately and efficiently realize the navigation and positioning of seafaring ships due to over-reliance on satellite navigation. Therefore, in the process of crew training, it is particularly important to enable crew members to understand the principles and experience of ship positioning under different sea conditions when satellite navigation fails. Traditional operation training usually relies on actual ship training, but there are certain limitations and problems. Due to the high cost of actual ship training, high safety risks and the inability to truly reproduce complex navigation environments, it is difficult to provide diversified and flexible operation training scenarios, which makes it impossible for crew members to effectively understand and master the principles and skills of ship positioning in various complex navigation environments. Summary of the invention

[0004] The present invention provides a ship positioning virtual training system based on a sextant simulator to overcome the above technical problems.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A sextant simulator-based ship positioning virtual training system includes a 3D modeling and reproduction module for obtaining the structure of the sextant simulator,

[0007] Data setting module for setting virtual positioning exercise data,

[0008] A simulation scenario construction module for setting a virtual training scenario at sea according to virtual positioning exercise data, and a virtual interactive training module for conducting virtual training of astronomical positioning and virtual training of landmark positioning according to the virtual training scenario at sea based on the sextant simulator structure obtained by the 3D modeling reproduction module;

[0009] A positioning model building module for obtaining an astronomical positioning model and a landmark positioning model;

[0010] The data setting module includes a script editing setting module for setting astronomical positioning training data and landmark positioning training data based on a positioning model construction module, a stage operation scoring module, and a comprehensive evaluation storage module;

[0011] The script editing and setting module is used to set the script data of the virtual positioning exercise about the navigation and positioning of the sailing ship through a preset editing interface, and set the sub-script data of several operation training stages in the script data according to the training type of the virtual positioning exercise;

[0012] The sub-script data is used to represent each operation training stage in the corresponding script data during the virtual positioning exercise;

[0013] The operation training stage at least includes an image movement simulation training stage for checking and correcting functions of a sextant moving mirror, an image movement simulation training stage for checking and correcting functions of a sextant fixed mirror, a sextant index difference measurement simulation training stage, and a sextant celestial body height measurement simulation training stage;

[0014] The stage operation scoring module is used to obtain the result data of executing the virtual interactive training, and to score the operation level of the result data of executing the training operation in each operation training stage based on a preset operation standard threshold;

[0015] The operation level is the score threshold obtained by artificial division according to the operation standard threshold;

[0016] The comprehensive evaluation storage module is used to obtain the result data and operation level score of each operation training stage, and obtain the virtual training result of ship navigation positioning according to the constructed astronomical positioning model or landmark positioning model based on the result data of each operation training stage;

[0017] Based on the error tolerance between the virtual training results and the actual ship navigation and positioning results, it is judged whether the virtual training of the trainees meets the standards, and based on the operation level score, the operation training stage that does not meet the virtual training requirements is confirmed so that targeted simulation training can be carried out.

[0018] Furthermore, the method for the positioning model building module to obtain the astronomical positioning model specifically includes the following steps:

[0019] S01: constructing a celestial body position mathematical model to obtain celestial body data in real time through the celestial body position mathematical model; and the celestial body data includes the celestial body altitude and the celestial body position;

[0020] To dynamically simulate and obtain the dynamic position of celestial bodies through celestial body models;

[0021] S02: Based on the sextant measurement method, obtain measurement data according to the dynamic position of the celestial body;

[0022] The measurement data at least include celestial body altitude and index difference measurement data;

[0023] And the index difference measurement data is the celestial body time angle excess;

[0024] According to the celestial body altitude data and index difference measurement data, combined with the ship navigation scene, the virtual ship position line is drawn and obtained to determine the ship position of the preset virtual ship, and the error triangle method is used to optimize the virtual ship position to obtain the astronomical positioning model.

[0025] Furthermore, the method for constructing the mathematical model of celestial body orientation in S01 is

[0026] S011: Construct the Julian day mathematical model, and calculate and obtain the Julian day parameter J according to the input year / month / day and universal time. Its expression is:

[0027]

[0028] Where: year represents the input year of the Julian day mathematical model; month represents the input month of the Julian day mathematical model; Date represents the input day of the Julian day mathematical model; CMT represents the input universal time of the Julian day mathematical model;

[0029] S012: According to the Julian day parameter J and the simulation time of the simulation scene of the virtual sextant simulator, the declination Dec and the local time angle LHA of the celestial body are obtained, and the expression is:

[0030]

[0031] Where: M represents the standard meridian of the simulated time zone; t s Indicates the simulation time of the simulation scenario;

[0032] S013: Based on the declination Dec and the local time angle LHA of the celestial body, construct a method for calculating the height h of the celestial body. c A c The mathematical model of celestial body orientation is expressed as

[0033]

[0034] Furthermore, the S02 specifically includes the following steps:

[0035] S021: Based on the sextant measurement method, obtain measurement data according to the dynamic position of celestial bodies;

[0036] According to the celestial body height data and the index difference measurement data, the true height h of the celestial body is obtained. t and the corresponding celestial local hour angle LHA1; its expression is

[0037] h t =h0+d+p1+p2

[0038]

[0039] Where: GHA represents the Greenwich hour angle of the observed celestial body; ms represents the basic variable of the Greenwich hour angle; v represents the hour angle deviation; represents the longitude of the virtual ship's environment; p1 represents the celestial body altitude correction; p2 represents the additional solar correction parameter; h0 represents the celestial body altitude measured by the sextant; d represents the eye height difference;

[0040] S022: Based on the celestial body local time angle LHA1, according to step S13, obtain the declination Dec of the geographical location point b corresponding to the observed celestial body position B;

[0041] S023: Take the virtual ship's position as the zenith Z c , the position of the celestial body B and the Earth's pole P N Draw an astronomical triangle for the vertex and project it onto the surface of the earth to obtain the projected triangle cbp n ;

[0042] With geographical location point b as the center and the true height of the celestial body h t As radius, draw the ship position curve II, and pass the ship position curve II and the projection triangle cbp n The intersection point k of the position curve II is the tangent point II-II of the position curve II, i.e., the position line;

[0043] S024: confirming the number of celestial bodies involved in the navigation and positioning of the ship, and the number of celestial bodies includes at least two or three;

[0044] If the number of celestial bodies is confirmed to be two, two ship position lines are obtained based on step S023, and the intersection of the two ship position lines is used as the ship position of the preset virtual ship. Its expression is

[0045]

[0046] Z 1,2 =90°-h t1,2

[0047] Where: Z 1,2 Indicates the intermediate parameter variable; h t1,2 Indicates the true altitude of the corresponding two celestial bodies;

[0048] If it is confirmed that the number of celestial bodies is three, three ship position lines are obtained based on step S023, and the intersection of the three ship position lines is used as the vertex to obtain the ship area positioning triangle;

[0049] The error triangle method is used to optimize the ship area positioning triangle, that is, the angle bisectors of the three angles of the ship area positioning triangle are obtained, and the intersection of the angle bisectors is used as the ship position of the preset virtual ship. Its expression is

[0050]

[0051] Where: R represents the radius of the earth; d i,j represents the spherical distance between any two vertices and i, j = 1, 2, 3.

[0052] Furthermore, the method for the positioning model building module to obtain the landmark positioning model specifically includes the following steps:

[0053] S001: Construct the number and height of landmarks used for ship positioning;

[0054] The number of the objects is at least two or three;

[0055] S002: If the number of objects is confirmed to be two, obtain the known height H of the object through the sextant simulator obtained based on the 3D modeling reproduction module i The object marker M i The vertical angle α i , and according to the vertical angle α i Height H i Get the virtual ship object measurement distance D i , i=1,2;

[0056] The virtual ship object measurement distance D i The expression is

[0057]

[0058] S003: Using the sextant simulator to measure and obtain the virtual azimuth of the target object, and summing the virtual azimuth of the target object with the measurement error ΔC set according to the empirical value to obtain the true azimuth TB of the target object;

[0059] Two azimuth lines are drawn along the TB±180° direction, and the intersection of the two azimuth lines is used as the ship position of the preset virtual ship. The expression is:

[0060]

[0061] Where: M1(x1, y1)M2(x2, y2) represent the position coordinates of the two objects respectively; e represents the eccentricity of the elliptical meridian; D1 and D2 represent the measured distances from the virtual ship to the two objects respectively; A, B, C represent the intermediate parameters;

[0062] S004: If the number of objects is confirmed to be three, obtain the known object height H through the sextant simulator obtained based on the 3D modeling reproduction module i The object marker M i The vertical angle α i , and according to the vertical angle α i Height H iGet the virtual ship object measurement distance D i , i=1,2,3;

[0063] S005: Using the sextant simulator to measure and obtain the virtual azimuth of the target object, and summing the virtual azimuth of the target object with the measurement error ΔC to obtain the true azimuth TB of the target object;

[0064] And draw three azimuth lines along the TB±180° direction, and use the intersection of the three azimuth lines as vertices to obtain the ship area positioning triangle;

[0065] S006: The position of the preset virtual ship is determined according to the ship area positioning triangle using the center of gravity method, and its expression is:

[0066]

[0067]

[0068] Where: x 12 ,y 12 , x 13 ,y 13 , x 23 ,y 23 Indicates the coordinate position of the vertices of the ship area positioning triangle; M1(x1,y1), M2(x2,y2), M3(x3,y3) respectively represent the position coordinates of the three objects; θ mi represents the observation angle between the sextant simulator and each object, and i=1,2,3; M i,j Represents the distance between any two objects; x bc Indicates the horizontal coordinate of the center of gravity of the ship area positioning triangle; y bc Indicates the vertical coordinate of the center of gravity of the ship area positioning triangle.

[0069] Beneficial effects: The present invention provides a ship positioning virtual training system based on a sextant simulator, which can enable trainees to master the use of the sextant in a virtual environment by simulating the structure and operation logic of a real sextant, including functions such as line of sight adjustment, angle measurement and error correction, and by constructing a mathematical model of astronomical positioning and landmark positioning, and optimizing the positioning result by using an error triangle method, so that trainees can operate the sextant for high-precision ship positioning training; the sextant simulator enables trainees to operate the sextant for ship positioning training in a virtual environment, thus avoiding the complex scheduling and high cost in actual ship training; through systematic training and assessment, the trainees' operation level of the sextant can be evaluated in real time, which can effectively improve the trainees' operation ability of operating the sextant for astronomical and landmark positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0071] Figure 1 A schematic diagram of a sextant simulator virtual system of the present invention;

[0072] Figure 2 Draw a diagram for positioning two distances of the virtual observation ship position in this embodiment;

[0073] Figure 3 Draw a diagram for three-distance positioning of the virtual observation ship position in this embodiment;

[0074] Figure 4 This is a schematic diagram of the structure of the earth and celestial sphere in this embodiment;

[0075] Figure 5 This is a schematic diagram of the modeling process and effect of the virtual training simulation scene in this embodiment;

[0076] Figure 6 This is a schematic diagram of a 3D model of a sextant in this embodiment;

[0077] Figure 7 This is a rendering of the 3D modeling operation of the sextant in this embodiment;

[0078] Figure 8 This is a virtual simulation effect diagram of the sun in this embodiment;

[0079] Fig. 9 This is a virtual simulation effect diagram of Sagittarius in this embodiment;

[0080] Fig.10 This is a virtual simulation effect diagram of the Ursa Major in this embodiment;

[0081] Fig.11 This is the core block diagram of the sextant simulator virtual system in this embodiment. DETAILED DESCRIPTION

[0082] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0083] This embodiment provides a ship positioning virtual training system based on a sextant simulator. Figure 1 As shown, it includes a 3D modeling and reproduction module for obtaining the structure of the sextant simulator; wherein the 3D modeling and reproduction module is used to perform 3D modeling on the existing sextant simulator to obtain a virtually constructed sextant simulator, ensuring the consistency of the model with the appearance and layout of the real sextant, such as Figure 6 to Figure 7 As shown, in addition, the virtually constructed sextant simulator is imported into the Unity software to perform material assignment and lighting adjustment, and the hierarchical relationship and interactive area of ​​the model are set at the same time. Based on the virtually constructed sextant simulator, the sextant measurement principle model is constructed, that is, based on the plane mirror reflection principle, the target image is made to coincide with the horizontal line by adjusting the mirror angle to measure the altitude angle, and the angle measurement reading is composed of the whole angle, the minute angle and the small cursor value, which is consistent with the actual equipment; the altitude angle, the azimuth angle and the observation position and time are combined, and the position of the target in the horizontal and equatorial coordinate systems is obtained by the angle geometry method, and the method of the virtually constructed sextant simulator is realized by the existing known technology, which will not be described in detail here;

[0084] Data setting module for setting virtual positioning exercise data,

[0085] A simulation scenario building module for setting up virtual training scenarios at sea based on virtual positioning exercise data;

[0086] Specifically, Figure 5 As shown, the simulation scene construction module is based on the radar data, electronic chart data and high-resolution image data of a certain location acquired in advance, and adopts 3DMax modeling and Unity3D engine rendering technology to realize the construction of the virtual training scene at sea. The construction method of the virtual training scene at sea is an existing well-known technical means, which will not be described in detail here. It also includes the precise mathematical modeling of the position of celestial bodies such as the sun, Sagittarius, and Ursa Major based on astronomical principles, and the precise mathematical model of the position of celestial bodies is realized by pre-setting C# scripts. The simulation effect is as follows: Figures 8 to 10 As shown, the preset high-precision terrain data is imported to obtain the port and related building models to ensure the authenticity of the virtual environment;

[0087] A virtual interactive training module for conducting virtual training of astronomical positioning and landmark positioning based on virtual training scenarios at sea and the sextant simulator structure obtained by the 3D modeling reproduction module;

[0088] A positioning model building module for obtaining an astronomical positioning model and a landmark positioning model;

[0089] The data setting module includes a script editing setting module for setting astronomical positioning training data and landmark positioning training data based on a positioning model construction module, a stage operation scoring module, and a comprehensive evaluation storage module;

[0090] The script editing and setting module is used to set the script data of the virtual positioning exercise about the navigation and positioning of the sailing ship through a preset editing interface, and set the sub-script data of several operation training stages in the script data according to the training type of the virtual positioning exercise;

[0091] The sub-script data is used to represent each operation training stage in the corresponding script data during the virtual positioning exercise;

[0092] The operation training stage at least includes an image movement simulation training stage for checking and correcting functions of a sextant moving mirror, an image movement simulation training stage for checking and correcting functions of a sextant fixed mirror, a sextant index difference measurement simulation training stage, and a sextant celestial body height measurement simulation training stage;

[0093] Specifically, the virtual interaction training module is used to set the virtual sextant interaction function according to each operation training stage, which includes

[0094] Virtual interactive operation during the image motion simulation training phase of the sextant dynamic mirror inspection and correction function:

[0095] a. Place the sextant horizontally;

[0096] b. Squeeze the elastic clamp and rotate the indicator arm to between 30° and 40°;

[0097] c. Observe the sextant frame and the sextant frame reflection angle from the upper side of the sextant;

[0098] d. Adjust the calibration screws until the reflective viewing frame and the direct viewing frame are on the same horizontal line, and check that the alignment is complete;

[0099] Virtual interactive operation during the image motion simulation training phase of the sextant fixation mirror correction function:

[0100] a. Place the sextant vertically;

[0101] b. Aim the viewing angle at the target object and observe whether there is any error;

[0102] c. Adjust the calibration screw until the object marks on the telescope are no longer overlapped or separated, and the observed object marks are fully displayed. The fixed mirror inspection is completed;

[0103] Virtual interactive operation during the sextant index difference measurement simulation training phase:

[0104] Simulate the index difference phenomenon caused by the deviation of the sextant lens to generate a deviation effect consistent with the actual observation. At the same time, provide a water antenna, a star or the sun as a reference object. By adjusting the sextant calibration screw, the index difference can be eliminated and the measurement accuracy can be adjusted.

[0105] Virtual interactive operation of the sextant in the simulation training phase of measuring the altitude of celestial bodies:

[0106] Based on the reflection principle of plane mirrors, the incident angle of light is simulated to be equal to the reflection angle, and the process of measuring the altitude angle of celestial bodies is created. The angle of the sextant is adjusted so that the line of sight of the target celestial body coincides with the horizontal plane, and the altitude angle of the celestial body is measured.

[0107] The stage operation scoring module is used to obtain the result data of executing the virtual interactive training, and to score the operation level of the result data of executing the training operation in each operation training stage based on a preset operation standard threshold;

[0108] The operation level is the score threshold obtained by artificial division according to the operation standard threshold;

[0109] The comprehensive evaluation storage module is used to obtain the result data and operation level score of each operation training stage, and obtain the virtual training result of ship navigation positioning according to the constructed astronomical positioning model or landmark positioning model based on the result data of each operation training stage;

[0110] In a specific embodiment, the method for the positioning model building module to obtain the astronomical positioning model is as follows: Figures 2 to 4 , specifically including the following steps:

[0111] S01: constructing a celestial body position mathematical model to obtain celestial body data in real time through the celestial body position mathematical model; and the celestial body data includes the celestial body altitude and the celestial body position;

[0112] To dynamically simulate and obtain the dynamic position of celestial bodies through celestial body models;

[0113] Specifically, the method for constructing the mathematical model of celestial body orientation in S01 is:

[0114] S011: Construct the Julian day mathematical model, and calculate and obtain the Julian day parameter J according to the input year / month / day and universal time. Its expression is:

[0115]

[0116] Where: year represents the input year of the Julian day mathematical model; month represents the input month of the Julian day mathematical model; Date represents the input day of the Julian day mathematical model; GMT represents the input universal time of the Julian day mathematical model;

[0117] S012: According to the Julian day parameter J and the simulation time of the simulation scene of the virtual sextant simulator, the declination Dec and the local time angle LHA of the celestial body are obtained, and the expression is:

[0118]

[0119] Where: M represents the standard meridian of the simulated time zone; t s Indicates the simulation time of the simulation scenario;

[0120] S013: Based on the declination Dec and the local time angle LHA of the celestial body, construct a method for calculating the height h of the celestial body. c A c The mathematical model of celestial body orientation is expressed as

[0121]

[0122] S02: Based on the sextant measurement method, obtain measurement data according to the dynamic position of the celestial body;

[0123] The measurement data at least include celestial body altitude and index difference measurement data;

[0124] And the index difference measurement data is the celestial body time angle excess;

[0125] According to the celestial body altitude data and index difference measurement data, combined with the ship navigation scene, a virtual ship position line is drawn and obtained to determine the ship position of the preset virtual ship, and the error triangle method is used to optimize the virtual ship position to obtain the astronomical positioning model;

[0126] Specifically, the S02 comprises the following steps:

[0127] S021: Based on the sextant measurement method, obtain measurement data according to the dynamic position of celestial bodies;

[0128] According to the celestial body height data and the index difference measurement data, the true height h of the celestial body is obtained. t and the corresponding celestial local hour angle LHA1; its expression is

[0129] h t =h0+d+p1+p2

[0130]

[0131] Where: GHA represents the Greenwich hour angle of the observed celestial body; ms represents the basic variable of the Greenwich hour angle; v represents the hour angle deviation; represents the longitude of the virtual ship's environment; p1 represents the celestial body altitude correction; p2 represents the additional solar correction parameter; h0 represents the celestial body altitude measured by the sextant; d represents the eye height difference;

[0132] S022: Based on the celestial body local time angle LHA1, according to step S13, obtain the declination Dec of the geographical location point b corresponding to the observed celestial body position B;

[0133] S023: Take the virtual ship's position as the zenith Z c, the position of the celestial body B and the Earth's pole P N Draw an astronomical triangle for the vertex and project it onto the surface of the earth to obtain the projected triangle cbp n ;

[0134] With geographical location point b as the center and the true height of the celestial body h t As radius, draw the ship position curve II, and pass the ship position curve II and the projection triangle cbp n The intersection point k of the ship position curve II is obtained by obtaining the tangent point II-II of the ship position curve II, i.e., the ship position line; wherein the method or means for drawing the ship position curve is the existing known technical content, and is not the invention of the present application, and the drawing process will not be described in detail here;

[0135] S024: confirming the number of celestial bodies involved in the navigation and positioning of the ship, and the number of celestial bodies includes at least two or three;

[0136] If the number of celestial bodies is confirmed to be two, two ship position lines are obtained based on step S023, and the intersection of the two ship position lines is used as the ship position of the preset virtual ship. Its expression is

[0137]

[0138] Z 1,2 =90°-h t1,2

[0139] Where: Z 1,2 Indicates the intermediate parameter variable; h t1,2 Indicates the true altitude of the corresponding two celestial bodies;

[0140] If it is confirmed that the number of celestial bodies is three, three ship position lines are obtained based on step S023, and the intersection of the three ship position lines is used as the vertex to obtain the ship area positioning triangle;

[0141] The error triangle method is used to optimize the ship area positioning triangle, that is, the angle bisectors of the three angles of the ship area positioning triangle are obtained, and the intersection of the angle bisectors is used as the ship position of the preset virtual ship. Its expression is

[0142]

[0143] Where: R represents the radius of the earth; d i,j represents the spherical distance between any two vertices and i, j = 1, 2, 3;

[0144] This embodiment also includes a method for optimizing the ship position of a preset virtual ship by using an error radius, specifically: obtaining the optimal position of the ship by a weighted average method, and its expression is:

[0145]

[0146] Where: p i Indicates the ship position of the preset virtual ship; E σi represents the random error of the i-th ship position line;

[0147] The error radius r is used to further correct the ship position to reduce the error of the optimal position of the ship. Its expression is:

[0148]

[0149] Where: θ represents the angle between the ship’s position lines at two adjacent points; E σ Indicates the random error of the ship position line;

[0150] Specifically, the method for the positioning model building module to obtain the landmark positioning model specifically includes the following steps:

[0151] S001: Construct the number and height of landmarks used for ship positioning;

[0152] The number of the objects is at least two or three;

[0153] S002: If the number of objects is confirmed to be two, obtain the known height H of the object through the sextant simulator obtained based on the 3D modeling reproduction module i The object marker M i The vertical angle α i , and according to the vertical angle α i Height H i Get the virtual ship object measurement distance D i , i=1,2;

[0154] The virtual ship object measurement distance D i The expression is

[0155]

[0156] S003: Using the sextant simulator to measure and obtain the virtual azimuth of the target object, and summing the virtual azimuth of the target object with the measurement error ΔC set according to the empirical value to obtain the true azimuth TB of the target object;

[0157] Two azimuth lines are drawn along the TB±180° direction, and the intersection of the two azimuth lines is used as the ship position of the preset virtual ship. The expression is:

[0158]

[0159] Where: M1(x1, y1)M2(x2, y2) represent the position coordinates of the two objects respectively; e represents the eccentricity of the elliptical meridian; D1 and D2 represent the measured distances from the virtual ship to the two objects respectively; A, B, C represent the intermediate parameters;

[0160] In this embodiment, the ship position of the preset virtual ship is obtained according to S003, and the distance position is obtained by The error circle radius r is optimized to obtain the optimal ship position, and its expression is:

[0161]

[0162] Where: ε B Indicates the systematic error; Indicates the distance from the ship to the target measured by the sextant; E σ represents the random error of the ship's position line; θ represents the azimuth angle between the two azimuth lines;

[0163] S004: If the number of objects is confirmed to be three, obtain the known object height H through the sextant simulator obtained based on the 3D modeling reproduction module i The object marker M i The vertical angle α i , and according to the vertical angle α i Height H i Get the virtual ship object measurement distance D i , i=1,2,3;

[0164] S005: Using the sextant simulator to measure and obtain the virtual azimuth of the target object, and summing the virtual azimuth of the target object with the measurement error ΔC to obtain the true azimuth TB of the target object;

[0165] And draw three azimuth lines along the TB±180° direction, and use the intersection of the three azimuth lines as vertices to obtain the ship area positioning triangle;

[0166] S006: The position of the preset virtual ship is determined according to the ship area positioning triangle using the center of gravity method, and its expression is:

[0167]

[0168] Where: x 12 ,y 12 , x 13 ,y 13 , x 23 ,y 23 Indicates the coordinate position of the vertices of the ship area positioning triangle; M1(x1,y1), M2(x2,y2), M3(x3,y3) respectively represent the position coordinates of the three objects; θ mirepresents the observation angle between the sextant simulator and each object, and i=1,2,3; M i,j Represents the distance between any two objects; x bc Indicates the horizontal coordinate of the center of gravity of the ship area positioning triangle; y bc Indicates the vertical coordinate of the center of gravity of the ship area positioning triangle.

[0169] In this embodiment, the final ship position p is also included 最优 , and optimized by the error circle radius r:

[0170]

[0171] Where: E σi represents the random error of the i-th azimuth line; θ i Indicates the angle between the azimuth lines of two adjacent objects; D i is the distance from the ship to the target object measured by the sextant, i = 1, 2, 3;

[0172] Based on the error tolerance between the virtual training results and the actual ship navigation and positioning results, it is judged whether the virtual training of the trainees meets the standards, and based on the operation level score, the operation training stage that does not meet the virtual training requirements is confirmed so that targeted simulation training can be carried out.

[0173] In this embodiment, the operation demonstration implementation case of the training and assessment module for landmark distance positioning is as follows:

[0174] S100: Enter the pre-set student ID to log into the system, select landmark distance positioning training after logging in, set the scene to the waters of China's Zhongshan Islands, the ship speed is 8 knots, the heading is 92.8°, and the landmark observation parameters are shown in Table 1;

[0175] Table 1. Virtual training scene landmark parameters

[0176]

[0177] S200: The trainee uses the virtual interactive training module to obtain the virtual sextant simulator constructed by the 3D modeling reproduction module based on the set script to adjust the moving mirror and the fixed mirror of the sextant so as to make the top of the target landmark coincide with the horizontal line and read the sextant data;

[0178] S300: input the vertical angle and height data of Xiaoban Island, Huangxing Island and Dongfu Mountain measured by the sextant into the landmark positioning model, and obtain the distance between the ship and the target as shown in Table 2 according to the landmark positioning model;

[0179] Table 2. Virtual training scene landmark parameters

[0180]

[0181] S400: deriving the vertex coordinates of the error triangle according to the data in Table 2, and comparing the vertex coordinates of the estimated error triangle with the coordinates of the electronic chart in the training system through Table 3;

[0182] Table 3. Comparison of estimated error triangle and actual error triangle

[0183]

[0184] S500: Set the random error standard deviation σ B =1.5°, the three-distance positioning error radius is obtained by the object distance calculation results in Table 2 and the three-distance ship position error radius formula, which is 0.0041nmile, the virtual ship position is calculated to be (122.5569, 30.1659), and the virtual ship position in the scene is (122.5580, 30.1657), and the actual error of the ship positioning at the three-object distance is 0.00118nmile, and the positioning training and assessment are passed;

[0185] In this embodiment, the sextant simulator virtual system is as follows: Fig.11 As shown, it also includes sextant virtual operation teaching, training and assessment modules: it is used to guide students to master the inspection and correction operation of the moving mirror and fixed mirror of the sextant through pictures, texts and videos; it also simulates actual operation to help students master the correction method, and simultaneously displays the reading and adjustment functions; at the same time, it sets the error threshold, evaluates the students' operation performance and generates performance records to ensure that students are proficient in sextant operation;

[0186] Sextant index difference measurement teaching, training and assessment module: guide students to master the index difference measurement method through virtual operation. Simulate the operation in the training stage, and students learn to measure the solar apparent radius with sextant. In the assessment stage, set the error range, evaluate the students' operation accuracy and record the results.

[0187] Teaching, training and assessment module for measuring the altitude of celestial bodies with sextant: This module guides students to master the measurement skills of the altitude angle of celestial bodies through pictures, texts and videos. During the training phase, students adjust the alignment of the sextant with the celestial body to simulate the measurement of the altitude. On the basis of the training mode, students add observation time weight and accuracy threshold for assessment.

[0188] Demonstration and interaction module of the basic principles of astronomy and landmark positioning: the working principles of astronomy and landmark positioning models are dynamically displayed in a virtual scene, and interactive functions are added to enable students to understand the principles of astronomy and landmark positioning through operation;

[0189] Sea sun shift positioning teaching, training and assessment module: Train trainees to use sextant to measure altitude angle, azimuth angle and sun shift positioning method, equipped with random questions and assessment functions to improve practical operation ability;

[0190] Distance positioning teaching, training and assessment module: Based on the landmark positioning model, the landmark positioning process is simulated to train trainees to use sextant for accurate distance measurement and positioning. The system demonstrates the basic principles and steps, and after training, the training is scored based on parameters such as positioning accuracy and operation time, and the corresponding assessment results are provided to improve the trainees' operational capabilities.

[0191] Three-star positioning teaching, training and assessment module: Based on the astronomical positioning model, the system simulates the astronomical positioning process and displays in detail the principles and steps of three-star positioning. It aims to train students to use sextant for precise astronomical positioning. After students complete operation training in a virtual environment, the system scores them based on indicators such as operation efficiency and provides assessment results.

[0192] Comprehensive evaluation system module: set the test content through the background, conduct random questions, customized tasks and assessments, record the operation results, operation steps and other contents of each evaluation point in the student's single or comprehensive practical simulation, and automatically give scores based on the recorded results combined with the evaluation mathematical model, so that students can conduct targeted training based on the scoring results.

[0193] In this embodiment, by simulating the structure and operation logic of a real sextant, including functions such as line of sight adjustment, angle measurement, and error correction, the trainees can master the use of the sextant in a virtual environment. By constructing mathematical models of astronomical positioning and landmark positioning, and optimizing the positioning results using methods such as error triangle and error radius, the trainees can operate the sextant for high-precision ship positioning training. The sextant simulator enables the trainees to operate the sextant for ship positioning training in a virtual environment, thus avoiding the complex scheduling and high cost in real ship training. Through systematic training and assessment, the trainees' operation level of the sextant can be evaluated in real time, which can effectively improve the trainees' operation ability of operating the sextant for astronomical and landmark positioning.

[0194] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ship positioning virtual training system based on a sextant simulator, characterized in that: Includes 3D modeling and reproduction module for obtaining the structure of the sextant simulator, Data setting module for setting virtual positioning exercise data, A simulation scenario construction module for setting a virtual training scenario at sea according to virtual positioning exercise data, and a virtual interactive training module for conducting virtual training of astronomical positioning and virtual training of landmark positioning according to the virtual training scenario at sea based on the sextant simulator structure obtained by the 3D modeling reproduction module; A positioning model building module for obtaining an astronomical positioning model and a landmark positioning model; The data setting module includes a script editing setting module for setting astronomical positioning training data and landmark positioning training data based on a positioning model construction module, a stage operation scoring module, and a comprehensive evaluation storage module; The script editing and setting module is used to set the script data of the virtual positioning exercise about the navigation and positioning of the sailing ship through a preset editing interface, and set the sub-script data of several operation training stages in the script data according to the training type of the virtual positioning exercise; The sub-script data is used to represent each operation training stage in the corresponding script data during the virtual positioning exercise; The operation training stage at least includes an image movement simulation training stage for checking and correcting functions of a sextant moving mirror, an image movement simulation training stage for checking and correcting functions of a sextant fixed mirror, a sextant index difference measurement simulation training stage, and a sextant celestial body height measurement simulation training stage; The stage operation scoring module is used to obtain the result data of executing the virtual interactive training, and to score the operation level of the result data of executing the training operation in each operation training stage based on a preset operation standard threshold; The operation level is the score threshold obtained by artificial division according to the operation standard threshold; The comprehensive evaluation storage module is used to obtain the result data and operation level score of each operation training stage, and obtain the virtual training result of ship navigation positioning according to the constructed astronomical positioning model or landmark positioning model based on the result data of each operation training stage; Based on the error tolerance between the virtual training results and the actual ship navigation and positioning results, it is judged whether the virtual training of the trainees meets the standards, and based on the operation level score, the operation training stage that does not meet the virtual training requirements is confirmed so that targeted simulation training can be carried out.

2. A ship positioning virtual training system based on a sextant simulator according to claim 1, characterized in that: The method for the positioning model building module to obtain the astronomical positioning model specifically comprises the following steps: S01: constructing a celestial body position mathematical model to obtain celestial body data in real time through the celestial body position mathematical model; and the celestial body data includes the celestial body altitude and the celestial body position; To dynamically simulate and obtain the dynamic position of celestial bodies through celestial body models; S02: Based on the sextant measurement method, obtain measurement data according to the dynamic position of the celestial body; The measurement data at least include celestial body altitude and index difference measurement data; And the index difference measurement data is the celestial body time angle excess; According to the celestial body altitude data and index difference measurement data, combined with the ship navigation scene, the virtual ship position line is drawn and obtained to determine the ship position of the preset virtual ship, and the error triangle method is used to optimize the virtual ship position to obtain the astronomical positioning model.

3. A ship positioning virtual training system based on sextant simulator according to claim 2, characterized in that: The method for constructing the mathematical model of celestial body orientation in S01 is: S011: Construct the Julian day mathematical model, and calculate and obtain the Julian day parameter J according to the input year / month / day and universal time. Its expression is: Where: year represents the input year of the Julian day mathematical model; month represents the input month of the Julian day mathematical model; Date represents the input day of the Julian day mathematical model; GMT represents the input universal time of the Julian day mathematical model; S012: According to the Julian day parameter J and the simulation time of the simulation scene of the virtual sextant simulator, the declination Dec and the local time angle LHA of the celestial body are obtained, and the expression is: Where: M represents the standard meridian of the simulated time zone; t s Indicates the simulation time of the simulation scenario; S013: Based on the declination Dec and the local time angle LHA of the celestial body, construct a method for calculating the height h of the celestial body. c A c The mathematical model of celestial body orientation is expressed as 4. A ship positioning virtual training system based on sextant simulator according to claim 3, characterized in that: The S02 specifically includes the following steps: S021: Based on the sextant measurement method, obtain measurement data according to the dynamic position of celestial bodies; According to the celestial body height data and the index difference measurement data, the true height h of the celestial body is obtained. t The corresponding celestial local hour angle LHA1; its expression is h t =h0+d+p1+p2 Where: GHA represents the Greenwich hour angle of the observed celestial body; ms represents the basic variable of the Greenwich hour angle; v represents the hour angle deviation; represents the longitude of the virtual ship's environment; p1 represents the celestial body altitude correction; p2 represents the additional solar correction parameter; h0 represents the celestial body altitude measured by the sextant; d represents the eye height difference; S022: Based on the celestial body local time angle LHA1, according to step S13, obtain the declination Dec of the geographical location point b corresponding to the observed celestial body position B; S023: Take the virtual ship's position as the zenith Z c , the position of the celestial body B and the Earth's pole P N Draw astronomical triangles for the vertices and project them onto the surface of the Earth to obtain projected triangles; With geographical location point b as the center and the true height of the celestial body h t As radius, draw the ship position curve II, and obtain the ship position curve tangent point II-II of the ship position curve II, i.e., the ship position line, through the intersection point k of the ship position curve II and the projection triangle; S024: confirming the number of celestial bodies involved in the navigation and positioning of the ship, and the number of celestial bodies includes at least two or three; If the number of celestial bodies is confirmed to be two, two ship position lines are obtained based on step S023, and the intersection of the two ship position lines is used as the ship position of the preset virtual ship. Its expression is Z 1,2 =90°-h t1,2 Where: Z 1,2 Indicates the intermediate parameter variable; h t1,2 Indicates the true altitude of the corresponding two celestial bodies; If it is confirmed that the number of celestial bodies is three, three ship position lines are obtained based on step S023, and the intersection of the three ship position lines is used as the vertex to obtain the ship area positioning triangle; The error triangle method is used to optimize the ship area positioning triangle, that is, the angle bisectors of the three angles of the ship area positioning triangle are obtained, and the intersection of the angle bisectors is used as the ship position of the preset virtual ship. Its expression is Where: R represents the radius of the earth; d i,j represents the spherical distance between any two vertices and i, j = 1, 2, 3.

5. The ship positioning virtual training system based on sextant simulator according to claim 1 is characterized in that: The method for the positioning model building module to obtain the landmark positioning model specifically comprises the following steps: S001: Construct the number and height of landmarks used for ship positioning; The number of the objects is at least two or three; S002: If the number of objects is confirmed to be two, obtain the known height H of the object through the sextant simulator obtained based on the 3D modeling reproduction module i The object marker M i The vertical angle α i , and according to the vertical angle α i Height H i Get the virtual ship object measurement distance D i , i=1,2; The virtual ship object measurement distance D i The expression is S003: Using the sextant simulator to measure and obtain the virtual azimuth of the target object, and summing the virtual azimuth of the target object with the measurement error ΔC set according to the empirical value to obtain the true azimuth TB of the target object; Two azimuth lines are drawn along the TB±180° direction, and the intersection of the two azimuth lines is used as the ship position of the preset virtual ship. The expression is: Where: M1(x1, y1)M2(x2, y2) represent the position coordinates of the two objects respectively; e represents the eccentricity of the elliptical meridian; D1 and D2 represent the measured distances from the virtual ship to the two objects respectively; A, B, C represent the intermediate parameters; S004: If the number of objects is confirmed to be three, obtain the known object height H through the sextant simulator obtained based on the 3D modeling reproduction module i The object marker M i The vertical angle α i , and according to the vertical angle α i Height H i Get the virtual ship object measurement distance D i , i=1,2,3; S005: Using the sextant simulator to measure and obtain the virtual azimuth of the target object, and summing the virtual azimuth of the target object with the measurement error ΔC to obtain the true azimuth TB of the target object; And draw three azimuth lines along the TB±180° direction, and use the intersection of the three azimuth lines as vertices to obtain the ship area positioning triangle; S006: The position of the preset virtual ship is determined according to the ship area positioning triangle using the center of gravity method, and its expression is: Where: x 12 ,y 12 , x 13 ,y 13 , x 23 ,y 23 Indicates the coordinate position of the vertices of the ship area positioning triangle; M1(x1,y1), M2(x2,y2), M3(x3,y3) respectively represent the position coordinates of the three objects; θ mi represents the observation angle between the sextant simulator and each object, and i=1,2,3; M i,j Represents the distance between any two objects; x bc Indicates the horizontal coordinate of the center of gravity of the ship area positioning triangle; y bc Indicates the vertical coordinate of the center of gravity of the ship area positioning triangle.

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