Shipborne inertial and starlight integrated calibration method and equipment based on external velocity damping

Abstract

The present invention relates to the field of combined navigation technology, and provides a shipborne inertial and starlight integrated calibration method and equipment based on external velocity damping. The method comprises obtaining a horizontal damping network of an inertial navigation system; obtaining the inertial navigation output latitude and inertial navigation output longitude of the inertial navigation system based on the horizontal damping network; selecting a horizontal damping parameter, establishing a state equation and a measurement equation of the star-inertial system under horizontal damping conditions; obtaining a Kalman filter based on the state equation and the measurement equation; obtaining a ship maneuvering condition through inertial navigation information, and when the ship maneuvering condition is met, performing integrated calibration of the inertial navigation system through the star-inertial combined system, and completing error estimation and compensation through the Kalman filter. The present invention compensates for the dynamic attitude measurement error of the inertial navigation by designing a Kalman filter with horizontal velocity damping, assisting star-sensitive equipment in achieving high-precision positioning, completing the integrated calibration of the star-inertial combined system, and maintaining the navigation accuracy of the inertial navigation system for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated navigation, and in particular to a shipborne inertia and starlight integrated calibration method and equipment based on external velocity damping. Background Art

[0002] While satellite navigation technology offers the advantages of high positioning accuracy and all-weather continuous navigation, the increasing diversity and sophistication of satellite signal jamming and deception methods poses significant challenges to its reliability in certain extreme marine applications. To address the satellite navigation denial conditions found in shipboard environments, a shipboard inertial and starlight calibration method based on external velocity damping of the ship's odometer has been designed. However, in marine environments, factors such as inertial component accuracy and the demands of long-duration navigation can lead to increasing divergence in navigation accuracy. When the inertial navigation system is critical, changes in the zero position of the undamped inertial navigation system can easily cause error oscillations and divergence, directly affecting the accuracy of the auxiliary star sensor's horizon information and, consequently, the navigation accuracy of the inertial navigation system. Summary of the Invention

[0003] The present invention aims to address at least one of the technical problems existing in the related art. To this end, the present invention provides a shipborne inertial and starlight integrated calibration method and equipment based on external velocity damping. This method combines the astronomical position information output by a star sensor with the shipborne horizontal damping condition, and then combines it with the position and attitude information of the inertial navigation system after coordinate system conversion. The horizontal information provided to the star sensor is corrected based on filtering errors, thereby ensuring positioning accuracy under valid star sensor conditions, meeting the integrated calibration conditions of the satellite-inertial combined system, and combining the inertial navigation system positioning and heading correction technology to complete the integrated calibration of the combined system, thereby achieving the purpose of extending the readjustment period of the satellite-inertial combined system.

[0004] The present invention provides a shipborne inertia and starlight integrated calibration method based on external velocity damping, comprising:

[0005] S1: Decompose the electronic odometer speed into horizontal speed through heading, input it into the inertial navigation system, and obtain the horizontal damping network of the inertial navigation system;

[0006] S2: Obtain the inertial navigation system's output latitude and longitude according to the inertial navigation system's horizontal damping network;

[0007] S3: Select horizontal damping parameters and establish the state equation of the satellite-inertial system under horizontal damping conditions according to the horizontal damping parameters;

[0008] S4: Establish the measurement equation of the inertial navigation system under horizontal damping conditions based on the inertial navigation output latitude, inertial navigation output longitude and starlight information;

[0009] S5: Obtain a Kalman filter based on the state equation and the measurement equation;

[0010] S6: Obtain the ship maneuvering conditions through inertial navigation information. When the ship maneuvering conditions are met, the inertial navigation system is comprehensively calibrated through the satellite-inertial combination system, and the error estimation and compensation are completed through the Kalman filter.

[0011] Furthermore, the calculation expressions for the inertial navigation system output longitude and the inertial navigation system output latitude are:

[0012]

[0013] in, Output longitude velocity for the inertial navigation system, is the eastward velocity calculated by inertial navigation, is the short radius of curvature of the Earth, Output latitude velocity for the inertial navigation system, is the north velocity calculated by the inertial navigation, is the long curvature radius of the Earth, is the initial longitude, is the initial longitude value, is the initial latitude, is the initial latitude value;

[0014] The inertial navigation system output longitude is obtained by integrating the inertial navigation system output longitude velocity, and the inertial navigation system output latitude is obtained by integrating the inertial navigation system output latitude velocity.

[0015] Furthermore, in step S3,

[0016] The system speed is obtained through the horizontal damping network, and the difference between the system speed and the reference speed is calculated to obtain the horizontal damping speed error. When horizontal damping is performed, the damping parameters are selected according to the horizontal damping speed error.

[0017] Furthermore, the state equation of the satellite-inertial system under horizontal damping conditions is calculated as follows:

[0018]

[0019] in, is the rate of change of the state variables of the star-inertial system, is the state variable of the star-inertial system, is the state matrix, is the noise matrix, is a noise sequence.

[0020] Furthermore, the measurement equation of the satellite-inertial system under horizontal damping conditions is:

[0021]

[0022]

[0023] in, is the inertial navigation system observation value under horizontal damping conditions, Output latitude for the inertial navigation system, Output longitude for the inertial navigation system, Convert latitude to geographic coordinate system for celestial navigation, Convert longitude to geographic coordinate system for celestial navigation. is the observation matrix, is the state estimate of the inertial navigation system under horizontal damping conditions, is the observed noise of the inertial navigation system under horizontal damping conditions.

[0024] Furthermore, the ship maneuvering conditions include judging through inertial navigation information that the ship's heading change rate is less than 15° / s, the ship's roll attitude change rate is less than 20° / s, the pitch attitude change rate is less than 10° / s, and the ship's total speed is less than 15Kn.

[0025] Furthermore, the comprehensive calibration method includes output calibration and feedback calibration,

[0026] In terms of heading calibration, the satellite inertial system adopts output calibration mode, and the heading calibration is not performed before the inertial navigation system has been working for 8 hours;

[0027] In position calibration,

[0028] If the inertial navigation system works for less than 18 hours, the satellite inertial system adopts the output calibration method;

[0029] If the inertial navigation system works for more than or equal to 18 hours, the satellite inertial system adopts feedback calibration mode;

[0030] After the position calibration of the satellite-inertial system is completed, the calibration flag of the satellite-inertial system is set to 0;

[0031] After repeating the position calibration N times, the calibration flag of the satellite-inertial combination system is set to 1.

[0032] Furthermore, step S6 includes:

[0033] S61: Comprehensive calibration of the inertial navigation system through the satellite-inertial system;

[0034] S62: Estimate the position and attitude of the inertial navigation system through the Kalman filter to obtain the equivalent celestial gyro drift error estimation and heading error estimation;

[0035] S63: Treating the estimated equivalent celestial gyro drift error as a vertical gyro drift error for compensation;

[0036] S64: The heading error estimate is compensated into the inertial navigation system through feedback calibration, and the attitude matrix is ​​corrected by the quaternion correction method.

[0037] Furthermore, in step S62,

[0038] Under horizontal damping conditions, the error propagation relationship of the system is:

[0039]

[0040] in, is the first intermediate variable, is the second intermediate variable, is the third intermediate variable, , is the change in latitude, is the longitude position error angle, is the increment of the Earth's rotation caused by the ground speed at the calibration time, , is the calibration start time, is the calibration time, is the Earth's rotational speed,

[0041] The calculation expression of the equivalent celestial gyro drift is:

[0042]

[0043] in, is the equivalent celestial gyro drift,

[0044] The calculation expression of the heading error estimate is:

[0045]

[0046] in, is the heading error angle.

[0047] The present invention also provides a shipborne inertia and starlight integrated calibration device based on external velocity damping, which is used to perform a shipborne inertia and starlight integrated calibration method based on external velocity damping, comprising:

[0048] a horizontal damping network acquisition module, which decomposes the electronic odometer speed into a horizontal speed according to the heading, and inputs the horizontal speed into the inertial navigation system to obtain the horizontal damping network of the inertial navigation system;

[0049] An output latitude and longitude acquisition module, wherein the output latitude and longitude acquisition module obtains the inertial navigation system output latitude and the inertial navigation system output longitude according to the horizontal damping network of the inertial navigation system;

[0050] A state equation building module, wherein the state equation building module selects a horizontal damping parameter and establishes a state equation of the satellite-inertial system under horizontal damping conditions according to the horizontal damping parameter;

[0051] A measurement equation building module, wherein the measurement equation building module establishes a measurement equation of the inertial navigation system under horizontal damping conditions according to the inertial navigation output latitude, the inertial navigation output longitude and starlight information;

[0052] A Kalman filter construction module, wherein the Kalman filter construction module obtains a Kalman filter according to a state equation and a measurement equation;

[0053] The integrated calibration module obtains the ship maneuvering conditions through inertial navigation information. When the ship maneuvering conditions are met, the inertial navigation system is comprehensively calibrated through the satellite-inertial combination system, and the error estimation and compensation are completed through the Kalman filter.

[0054] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0055] Through the ship's horizontal damping conditions combined with the astronomical position information output by the star sensor, after the coordinate system conversion, combined with the position and attitude information of the inertial navigation, the horizon information provided to the star sensor is corrected according to the filtering error, thereby ensuring the positioning accuracy under the effective conditions of the star sensor, meeting the comprehensive calibration conditions of the star-inertial combination system, combining the inertial navigation system positioning and heading correction technology, completing the star-inertial comprehensive calibration, thereby achieving the purpose of extending the readjustment period of the star-inertial combination system and maintaining the navigation accuracy of the inertial navigation system.

[0056] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the present invention or 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 any creative work.

[0058] Figure 1 The present invention provides a flow chart of a method for shipborne inertia and starlight integrated calibration based on external velocity damping.

[0059] Figure 2 The present invention provides a schematic diagram of a horizontal damping network for a shipborne inertia and starlight integrated calibration method based on external velocity damping.

[0060] Figure 3 The present invention provides a structural diagram of a shipborne inertia and starlight integrated calibration device based on external velocity damping.

[0061] Reference numerals:

[0062] 101. Horizontal damping network acquisition module; 102. Output latitude and longitude acquisition module; 103. State equation construction module; 104. Measurement equation construction module; 105. Kalman filter construction module; 106. Comprehensive calibration module. DETAILED DESCRIPTION

[0063] To make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below. Obviously, the embodiments described are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0064] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0065] The following combination Figures 1 to 3 The present invention describes a shipborne inertia and starlight integrated calibration method and equipment based on external velocity damping.

[0066] like Figure 1 As shown, a shipborne inertial and starlight integrated calibration method based on external velocity damping includes:

[0067] S1: Decompose the electronic odometer speed into horizontal speed through heading and input it into the inertial navigation system to obtain the horizontal damping network of the inertial navigation system;

[0068] Add a compensation channel in the inertial navigation system to complete the Schuler period damping of the inertial navigation system. The horizontal damping network is as follows: Figure 2 shown.

[0069] S2: Obtain the inertial navigation system's output latitude and longitude according to the inertial navigation system's horizontal damping network;

[0070] According to the horizontal damping network, the calculation expression of harmful acceleration can be obtained as follows:

[0071]

[0072] in, is the eastward horizontal damping harmful acceleration, Output latitude for the inertial navigation system, is the north velocity calculated by the inertial navigation, is the northward horizontal damping harmful acceleration, is the eastward velocity calculated by inertial navigation, Output longitude velocity for the inertial navigation system, is the Earth's rotational speed;

[0073]

[0074] in, is the eastward acceleration ratio of the navigation system, is the specific force value of the accelerometer in the eastward horizontal damping inertial link, is the speed increment of the feedback link of the eastward damping network, is the acceleration ratio of the navigation system to the north, is the velocity increment of the northbound damping network feedback link, is the accelerometer specific force value in the north horizontal damping inertial link, and the carrier acceleration vector Through the posture matrix Decomposition and .

[0075]

[0076] in, is the feedback speed difference of the eastward damping loop system, is the feedback speed difference of the eastward damping loop system, is the eastward reference velocity, is the north reference velocity, is the speed of the feedback link of the eastward damping network, is the speed of the feedback link of the eastward damping network,

[0077] The calculation expression of the radius of curvature of the earth is:

[0078]

[0079] in, is the long curvature radius of the Earth, is the short radius of curvature of the Earth, is the Earth's eccentricity, is the Earth's semi-major axis, is latitude;

[0080] Mathematical platform calculations:

[0081]

[0082] in, The east angular velocity of the mathematical platform control command, The north angular velocity of the mathematical platform control instruction, It is the mathematical platform control instruction celestial angular velocity, is the eastward velocity calculated by inertial navigation, is the north velocity calculated by the inertial navigation, is the equivalent eastward gyro drift compensated by inertial navigation, is the equivalent north gyro drift compensated by inertial navigation, is the equivalent celestial gyro drift compensated by inertial navigation, is the Earth's rotational speed,

[0083]

[0084] in, Output longitude velocity for the inertial navigation system, Output longitude for the inertial navigation system, is the eastward velocity calculated by inertial navigation, is the short radius of curvature of the Earth, Output latitude for the inertial navigation system, Output latitude velocity for the inertial navigation system, is the north velocity calculated by the inertial navigation, is the long curvature radius of the Earth, is the initial longitude, is the initial longitude value, is the initial latitude, is the initial latitude value,

[0085] The inertial navigation system output longitude is obtained by integrating the inertial navigation system output longitude velocity, and the inertial navigation system output latitude is obtained by integrating the inertial navigation system output latitude velocity. Figure 2 in Represents the points link.

[0086] S3: Select horizontal damping parameters and establish the state equation of the satellite-inertial system under horizontal damping conditions according to the horizontal damping parameters;

[0087] The system speed is obtained through the horizontal damping network. The difference between the system speed and the reference speed is calculated to obtain the horizontal damping speed error. The damping parameter is selected according to the horizontal damping speed error. When horizontal damping is used, the damping parameter is selected according to the following formula;

[0088]

[0089] in, is the damping coefficient of the inertial link in the horizontal damping network, is the damping coefficient of the integral link in the horizontal damping network, is the damping coefficient of the gain link in the horizontal damping network, for The horizontal damped velocity error at time .

[0090] For calculation of damping parameters, refer to the principles for selecting damping networks in "Inertial Navigation Systems" (Harbin Engineering University, March 1999), edited by Huang Deming and Cheng Lu. We will not elaborate on this here.

[0091] The state variables of the horizontal damping condition are:

[0092]

[0093] in, for Velocity error in direction, for Velocity error in direction, for Velocity error in direction, is the latitude position error angle, is the longitude position error angle, is the height position error angle, is the horizontal attitude error angle, is the vertical attitude error angle, is the heading error angle, is the intermediate variable in the dimensionality reduction of the eastward velocity damping network, is the intermediate variable in the dimensionality reduction of the northbound velocity damping network, is the intermediate variable in the dimensionality reduction of the highly damped network, for The constant drift of the gyro in the celestial direction, for The constant drift of the gyro in the celestial direction, is the equivalent celestial gyro drift, for Spinning Top Directional scale and shaft installation errors, for Spinning Top Directional scale and shaft installation errors, for Spinning Top Directional scale and shaft installation errors, for Spinning Top Directional scale and shaft installation errors, for Spinning Top Directional scale and shaft installation errors, for Spinning Top Directional scale and shaft installation errors, for Spinning Top Directional scale and shaft installation errors, for Spinning Top Directional scale and shaft installation errors, for Spinning Top Directional scale and shaft installation errors, is the easting equivalent zero position error in the geographic coordinate system, is the north equivalent zero position error in the geographic coordinate system, is the equivalent zero position error in the celestial direction under the geographic coordinate system, for Add a table The axis installation error in the direction, for Add a table The axis installation error in the direction, for Add a table The axis installation error in the direction, for Add a table The axis installation error in the direction, for Add a table The axis installation error in the direction, for Add a table The axis installation error in the direction, is the transpose of the matrix,

[0094]

[0095]

[0096] in, is the eastward input specific force of the accelerometer, is the accelerometer north input specific force, is the celestial input relative force of the accelerometer, is the eastward speed, is the northward velocity, is the celestial velocity, is the latitude, is the radius of the Earth, is the Earth's rotational speed, For reference external velocity Horizontal error, is the external reference speed within the sampling time Directional horizontal velocity increment error, For reference external velocity Directional horizontal error, is the external reference speed within the sampling time Directional horizontal velocity increment error, is the altimeter elevation difference, is the current gravity; is the damping coefficient of the inertial link in the horizontal damping network, is the damping coefficient of the integral link in the horizontal damping network, is the damping coefficient of the gain link in the horizontal damping network, is the inertia coefficient of the highly damped network, is the feedback coefficient of the highly damped network, is the gain coefficient of the highly damped network, is the gyro drift noise coefficient, is the gyro installation error matrix correlation coefficient, is the accelerometer zero-point noise coefficient, is the accelerometer installation error matrix correlation coefficient, is the equivalent acceleration force error of the eastward horizontal channel, is the equivalent acceleration force error of the north-facing horizontal channel, is the vertical channel acceleration specific force error, is the north angular velocity error of the carrier relative to the geographic coordinate system, is the eastward angular velocity error of the carrier relative to the geographic coordinate system, is the vertical channel velocity error, is the roll angular velocity error, is the pitch angular velocity error, is the heading angular velocity error, is the velocity increment when the eastward velocity damping network is reduced in dimension, is the velocity increment when the northbound velocity damping network is reduced in dimension, is the velocity increment when the vertical velocity damping network is reduced in dimension, for Directional gyro installation error change rate, for Directional gyro installation error change rate, for Directional gyro installation error change rate, for Spinning Top Directional scale and axis installation error change rate, for Spinning Top Directional scale and axis installation error change rate, for Spinning Top Directional scale and axis installation error change rate, for Spinning Top Directional scale and axis installation error change rate, for Spinning Top Directional scale and axis installation error change rate, for Spinning Top Directional scale and axis installation error change rate, for Spinning Top Directional scale and axis installation error change rate, for Spinning Top Directional scale and axis installation error change rate, for Spinning Top Directional scale and axis installation error change rate, is the rate of change of the eastward equivalent zero position error in the geographic coordinate system, is the rate of change of the north equivalent zero position error in the geographic coordinate system is the rate of change of the equivalent zero position error in the geographic coordinate system, Add a table The rate of change of the shafting installation error in the direction, for Add a table The rate of change of the shafting installation error in the direction, for Add a table The rate of change of the shafting installation error in the direction, for Add a table The rate of change of the shafting installation error in the direction, for Add a table The rate of change of the shafting installation error in the direction, for Add a table The axis installation error in the direction, is the transpose of the matrix;

[0097] The state equations of the inertial navigation system and astronomical system under horizontal damping conditions are established according to the horizontal damping parameters;

[0098] The calculation expression of the system's state equation is:

[0099]

[0100] in, is the rate of change of the system's state variables, is the state variable of the system, is the noise matrix, is a noise sequence, , is the state matrix, , Solve the correlation matrix for navigation, is the correlation matrix of inertial element errors in navigation solution, is the correlation matrix of inertial component noise and installation error, The expression is:

[0101]

[0102]

[0103] The expression is:

[0104]

[0105] The expression is:

[0106]

[0107] in, is the correlation matrix of gyro drift and gyro installation error, is the correlation matrix of accelerometer zero position and accelerometer installation error,

[0108] The expression is:

[0109]

[0110]

[0111] The expression is:

[0112]

[0113] The calculation expression is:

[0114]

[0115] in, is the system noise matrix, is the identity matrix;

[0116]

[0117] S4: Establish the measurement equation of the inertial navigation system under horizontal damping conditions based on the inertial navigation output latitude, inertial navigation output longitude and starlight information;

[0118] The star sensor measures the output to get the optical axis direction: , the horizontal axis points to: ;

[0119] in, is the direction of the optical axis, Optical axis direction Axial component, Optical axis direction Axial component, Optical axis direction Axial component, is the horizontal axis direction, The horizontal axis points Axial component, The horizontal axis points Axial component, The horizontal axis points Axial component;

[0120] The Y-axis direction of the star sensor can be obtained from the optical axis direction and the horizontal axis direction:

[0121] =

[0122] in, is the Y-axis direction, Y-axis direction Axial component, Y-axis direction Axial component, Y-axis direction Axial component, is the tensor product;

[0123] Therefore, the inertial attitude direction cosine matrix obtained by the star sensor is ,

[0124]

[0125] When providing horizon information to Xingmin, If only position and heading information is included, we can get:

[0126]

[0127] in, is the latitude position vector in the inertial coordinate system, is the longitude position vector in the inertial coordinate system, for The value of the 3rd row and 3rd column in for The value of row 3 and column 2 in for The value in row 3 and column 1.

[0128] Will Convert the world time to the geographic coordinate system. Convert to geographic coordinate system position according to universal time;

[0129] In the geographic coordinate system, the measurement equation with position and heading as observation quantities is:

[0130]

[0131] in, is the inertial navigation system observation value under horizontal damping conditions, To solve for latitude, To calculate longitude, Convert latitude to geographic coordinate system for celestial navigation, Convert longitude to geographic coordinate system for celestial navigation. is the observation matrix, is the state estimate of the inertial navigation system under horizontal damping conditions, is the inertial navigation system observation noise under horizontal damping conditions, is the 3D observation white noise.

[0132] S5: Obtain a Kalman filter based on the state equation and the measurement equation;

[0133] S6: Obtain the ship maneuvering conditions through inertial navigation information. When the ship maneuvering conditions are met, the inertial navigation system is comprehensively calibrated through the satellite-inertial combination system, and the error estimation and compensation are completed through the Kalman filter;

[0134] S61: Comprehensive calibration of the inertial navigation system through the satellite-inertial system;

[0135] Integrated calibration of a satellite-inertial navigation system involves obtaining one or more points of starlight position information, then recalibrating the system and performing error estimation based on horizontal damping. A horizontal damping filter, designed based on the characteristics of shipborne inertial navigation, compensates for the dynamic attitude errors of the inertial navigation system, ensuring the real-time accuracy of attitude information and the precision of the star-sensing horizon information. When performing integrated calibration of a satellite-inertial navigation system, two key considerations must be considered: first, the determination of the ship's maneuvering conditions; second, the application of integrated calibration of the satellite-inertial navigation system.

[0136] Ship maneuvering conditions include: judging by inertial navigation information that the ship's heading change rate is less than 15° / s, the ship's roll attitude change rate is less than 20° / s, the pitch attitude change rate is less than 10° / s, and the ship's total speed is less than 15kn;

[0137] The integrated calibration method includes output calibration and feedback calibration. During the navigation process, output calibration improves the accuracy of the final output by compensating for the errors in the displayed results without directly intervening in the error divergence law in the navigation solution process.

[0138] In terms of heading calibration, the satellite inertial system adopts output calibration mode, and the heading calibration is not performed before the inertial navigation system has been working for 8 hours;

[0139] In position calibration,

[0140] If the inertial navigation system works for less than 18 hours, the satellite inertial system adopts the output calibration method;

[0141] If the inertial navigation system works for more than or equal to 18 hours, the satellite inertial system adopts feedback calibration mode;

[0142] After the position calibration of the satellite-inertial system is completed, the calibration flag of the satellite-inertial system is set to 0;

[0143] After repeating the position calibration N times, the calibration flag of the satellite-inertial combination system is set to 1.

[0144] In some specific embodiments of the present invention, N is greater than or equal to 30.

[0145] S62: Estimate the position and attitude of the inertial navigation system through the Kalman filter to obtain the equivalent celestial gyro drift error estimation and heading error estimation;

[0146] Located in The moment the starlight reference position information is obtained is the calibration moment, and the position error at this moment is recorded as ; The heading error is recorded as ; The gyro drift in the geographic coordinate system is recorded as ,Since the inertial / starlight combined navigation system needs to rotate around the vertical axis when searching by starlight, the star-seeking strategy is designed to be forward and reverse star-seeking, which means that the horizontal gyro is fully modulated. It has an effect on the system error. Under the horizontal damping condition, the error propagation relationship of the system is:

[0147]

[0148] in, is the first intermediate variable, is the second intermediate variable, is the third intermediate variable, , is the change in latitude, is the longitude position error angle, is the increment of the Earth's rotation caused by the ground speed at the calibration time, , The calibration start time (when the first calibration is performed, the calibration start time is when the system enters the navigation state; when the calibration is completed, Record the current time as the calibration start time for the next calibration). is the calibration time, is the Earth's rotational speed,

[0149] The calculation expression of the equivalent celestial gyro drift is:

[0150]

[0151] in, is the equivalent celestial gyro drift,

[0152] The calculation expression of the heading error estimate is:

[0153]

[0154] in, is the heading error angle.

[0155] S63: Treating the estimated equivalent celestial gyro drift error as a vertical gyro drift error for compensation;

[0156] S64: The heading error estimate is compensated into the inertial navigation system through feedback calibration, and the attitude matrix is ​​corrected by the quaternion correction method.

[0157] According to the mathematical platform control instruction east angular velocity , mathematical platform control command north angular velocity , mathematical platform control command celestial angular velocity Through the posture matrix Get a spinning top Sensitive angular velocity increment in inertial frame , angular velocity increment under load system And the angular velocity increment under the navigation system ; Spinning top Sensitive angular velocity increment in inertial frame , angular velocity increment under load system And the angular velocity increment under the navigation system , gyroscope Sensitive angular velocity increment in inertial frame , angular velocity increment under load system And the angular velocity increment under the navigation system , the attitude matrix is ​​corrected by the quaternion algorithm. The solution method of the attitude matrix corrected by the quaternion algorithm can be found in Section 9 of "Inertial Navigation" (3rd edition) edited by Qin Yongyuan, which will not be repeated here.

[0158] like Figure 3 As shown, a shipborne inertial and starlight integrated calibration device based on external velocity damping is used to perform a shipborne inertial and starlight integrated calibration method based on external velocity damping, comprising:

[0159] The horizontal damping network acquisition module 101 decomposes the electronic odometer speed into horizontal speed through the heading and inputs it into the inertial navigation system to obtain the horizontal damping network of the inertial navigation system;

[0160] The output latitude and longitude acquisition module 102 obtains the inertial navigation system's output latitude and longitude according to the inertial navigation system's horizontal damping network;

[0161] The state equation building module 103 selects a horizontal damping parameter and builds a state equation of the satellite-inertial system under horizontal damping conditions according to the horizontal damping parameter;

[0162] The measurement equation building module 104 builds the measurement equation of the inertial navigation system under horizontal damping conditions according to the inertial navigation output latitude, the inertial navigation output longitude and the starlight information;

[0163] The Kalman filter construction module 105 obtains the Kalman filter according to the state equation and the measurement equation;

[0164] The integrated calibration module 106 obtains the ship maneuvering conditions through the inertial navigation information. When the ship maneuvering conditions are met, the inertial navigation system is comprehensively calibrated through the satellite-inertial combination system, and the error estimation and compensation are completed through the Kalman filter.

[0165] Through the coordinated work of the above modules, the astronomical position information output by the star sensor is combined with the ship-borne horizontal damping conditions, and after the coordinate system conversion, it is combined with the position and attitude information of the inertial navigation. The horizon information provided to the star sensor is corrected according to the filtering error, thereby ensuring the positioning accuracy under the effective conditions of the star sensor, meeting the comprehensive calibration conditions of the star-inertial combination system, combining the inertial navigation system positioning and heading correction technology, and completing the star-inertial comprehensive calibration, thereby achieving the purpose of extending the readjustment period of the star-inertial combination system and maintaining the navigation accuracy of the inertial navigation system.

[0166] 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 make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A shipborne inertial and starlight integrated calibration method based on external velocity damping, characterized in that: include: S1: Decompose the electronic odometer speed into horizontal speed through heading, input it into the inertial navigation system, and obtain the horizontal damping network of the inertial navigation system; S2: Obtain the inertial navigation system's output latitude and longitude according to the inertial navigation system's horizontal damping network; S3: Select horizontal damping parameters and establish the state equation of the satellite-inertial system under horizontal damping conditions according to the horizontal damping parameters; The system speed is obtained through the horizontal damping network. The difference between the system speed and the reference speed is calculated to obtain the horizontal damping speed error. The damping parameter is selected according to the horizontal damping speed error. When horizontal damping is used, the damping parameter is selected according to the following formula; in, is the damping coefficient of the inertial link in the horizontal damping network, is the damping coefficient of the integral link in the horizontal damping network, is the damping coefficient of the gain link in the horizontal damping network, for Horizontal damping velocity error at time ; S4: Establish the measurement equation of the inertial navigation system under horizontal damping conditions based on the inertial navigation output latitude, inertial navigation output longitude and starlight information; S5: Obtain a Kalman filter based on the state equation and the measurement equation; S6: Obtain the ship maneuvering conditions through inertial navigation information. When the ship maneuvering conditions are met, the inertial navigation system is comprehensively calibrated through the satellite-inertial combination system, and the error estimation and compensation are completed through the Kalman filter; Ship maneuvering conditions include: judging by inertial navigation information that the ship's heading change rate is less than 15° / s, the ship's roll attitude change rate is less than 20° / s, the pitch attitude change rate is less than 10° / s, and the ship's total speed is less than 15kn; The comprehensive calibration method includes output calibration and feedback calibration. In terms of heading calibration, the satellite inertial system adopts output calibration mode, and the heading calibration is not performed before the inertial navigation system has been working for 8 hours; In position calibration, If the inertial navigation system works for less than 18 hours, the satellite inertial system adopts the output calibration method; If the inertial navigation system works for more than or equal to 18 hours, the satellite inertial system adopts feedback calibration mode; After the position calibration of the satellite-inertial system is completed, the calibration flag of the satellite-inertial system is set to 0; After repeating the position calibration N times, the calibration flag of the satellite-inertial combination system is set to 1.

2. The shipborne inertial and starlight integrated calibration method based on external velocity damping according to claim 1 is characterized in that: In step S2, the calculation expressions of the inertial navigation system output longitude and latitude are: in, Output longitude velocity for the inertial navigation system, is the eastward velocity calculated by inertial navigation, is the short radius of curvature of the Earth, Output latitude velocity for the inertial navigation system, is the north velocity calculated by the inertial navigation, is the long curvature radius of the Earth, is the initial longitude, is the initial longitude value, is the initial latitude, is the initial latitude value; The inertial navigation system output longitude is obtained by integrating the inertial navigation system output longitude velocity, and the inertial navigation system output latitude is obtained by integrating the inertial navigation system output latitude velocity.

3. The shipborne inertial and starlight integrated calibration method based on external velocity damping according to claim 1 is characterized in that: The calculation expression of the state equation of the satellite-inertial system under horizontal damping conditions is: in, is the rate of change of the state variables of the star-inertial system, is the state variable of the star-inertial system, is the state matrix, is the noise matrix, is a noise sequence.

4. The shipborne inertial and starlight integrated calibration method based on external velocity damping according to claim 1 is characterized in that: The measurement equation of the satellite-inertial system under horizontal damping conditions is: in, is the inertial navigation system observation value under horizontal damping conditions, Output latitude for the inertial navigation system, Output longitude for the inertial navigation system, Convert latitude to geographic coordinate system for celestial navigation, Convert longitude to geographic coordinate system for celestial navigation. is the observation matrix, is the state estimate of the inertial navigation system under horizontal damping conditions, is the observed noise of the inertial navigation system under horizontal damping conditions.

5. The shipborne inertial and starlight integrated calibration method based on external velocity damping according to claim 1 is characterized in that: Step S6 includes: S61: Comprehensive calibration of the inertial navigation system through the satellite-inertial system; S62: Estimate the position and attitude of the inertial navigation system through the Kalman filter to obtain the equivalent celestial gyro drift error estimation and heading error estimation; S63: Treating the estimated equivalent celestial gyro drift error as a vertical gyro drift error for compensation; S64: The heading error estimate is compensated into the inertial navigation system through feedback calibration, and the attitude matrix is ​​corrected by the quaternion correction method.

6. The shipborne inertia and starlight integrated calibration method based on external velocity damping according to claim 5 is characterized in that: In step S62, Under horizontal damping conditions, the error propagation relationship of the system is: in, is the first intermediate variable, is the second intermediate variable, is the third intermediate variable, , is the change in latitude, is the longitude position error angle, is the increment of the Earth's rotation caused by the ground speed at the calibration time, , is the calibration start time, is the calibration time, is the Earth's rotational speed, The calculation expression of the equivalent celestial gyro drift is: in, is the equivalent celestial gyro drift; The calculation expression of the heading error estimate is: in, is the heading error angle.

7. A shipborne inertial and starlight integrated calibration device based on external velocity damping, characterized in that: The method for performing a shipborne inertial and starlight integrated calibration method based on external velocity damping as claimed in any one of claims 1 to 6 comprises: a horizontal damping network acquisition module, which decomposes the electronic odometer speed into a horizontal speed according to the heading, and inputs the horizontal speed into the inertial navigation system to obtain the horizontal damping network of the inertial navigation system; An output latitude and longitude acquisition module, wherein the output latitude and longitude acquisition module obtains the inertial navigation system output latitude and the inertial navigation system output longitude according to the horizontal damping network of the inertial navigation system; A state equation building module, wherein the state equation building module selects a horizontal damping parameter and establishes a state equation of the satellite-inertial system under horizontal damping conditions according to the horizontal damping parameter; A measurement equation building module, wherein the measurement equation building module establishes a measurement equation of the inertial navigation system under horizontal damping conditions according to the inertial navigation output latitude, the inertial navigation output longitude and starlight information; A Kalman filter construction module, wherein the Kalman filter construction module obtains a Kalman filter according to a state equation and a measurement equation; The integrated calibration module obtains the ship maneuvering conditions through inertial navigation information. When the ship maneuvering conditions are met, the inertial navigation system is comprehensively calibrated through the satellite-inertial combination system, and the error estimation and compensation are completed through the Kalman filter.

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