Active isolation type optical fiber platform high-precision transfer alignment method

Abstract

The invention discloses an active isolation type optical fiber platform high-precision transfer alignment method, and belongs to the technical field of inertial navigation. Based on an optical fiber platform system with a multi-axis rotating mechanism, a platform body can be controlled to rotate around a sky axis so as to improve the observability of the system, meanwhile, the optical fiber platform can isolate angular motion of a carrier in a space stable mode, the relative inertial space is kept stable, and the influence of external disturbance on the use precision of an instrument can be eliminated or reduced. According to the method, speed and position information provided by high-precision main inertial navigation is used as a reference, a high-order transfer alignment Kalman filtering model is constructed by adopting a speed + position matching mode, high-precision estimation of the attitude misalignment angle of the optical fiber platform body is realized, meanwhile, the zero offset error of an inertial instrument is estimated and compensated, and the precision of the optical fiber platform body attitude misalignment angle is improved. And the alignment performance is improved by fully utilizing the stability of the instrument. According to the invention, the problems of high requirement and low precision of the existing optical fiber platform inertial navigation in the aspect of transfer alignment of the movable base are solved.

Description

Technical Field

[0001] The invention relates to a high-precision transfer alignment method for an active isolation optical fiber platform, belonging to the technical field of inertial navigation. Background Art

[0002] The fiber optic gyro inertial platform system is a new type of platform inertial system. It is equipped with three high-precision fiber optic gyroscopes, which can directly measure the angular motion of the carrier. In addition, it has three rotation axes, which can make the platform assembly rotate around the rotation axis, and has "three self" functions. During the working process, it can not only control the rotation of the platform according to the predetermined indexing control strategy, but also use the output of the accelerometer and gyroscope to directly perform navigation solution on the platform.

[0003] The dynamic base transfer alignment of the inertial navigation system is affected by environmental factors such as carrier movement and low-frequency disturbances during navigation, and is also limited by factors such as carrier concealment, maneuverability and carrier deformation, which reduces the observability of the system. Under such external restrictions, the use of attitude matching information for transfer alignment cannot meet the use requirements. Traditional platform inertial navigation systems still use optical aiming solutions for transfer alignment, which requires the installation of complex optical paths on ships and regular calibration, which brings great difficulties to users' operation and use. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and provide a high-precision transfer alignment method for an actively isolated optical fiber platform, thereby improving the user's operability and alignment accuracy under the condition that the carrier is affected by environmental factors such as low-frequency disturbances of waves and is limited by factors such as the concealment, maneuverability and deformation of the carrier.

[0005] The technical solution of the present invention is: a high-precision transfer alignment method of an active isolation optical fiber platform, comprising:

[0006] S1, power on and heat the fiber optic platform inertial system, initialize parameters after the temperature stabilizes and meets the working conditions, and enter the transfer alignment process after the fiber optic platform frame is locked to zero;

[0007] S2, according to the gyroscope output signal of the fiber optic platform inertial system, calculate the angular velocity information sensed by the fiber optic platform body, and exert corresponding control on the fiber optic platform indexing mechanism to keep the fiber optic platform body stable relative to the inertial space;

[0008] S3, controlling the fiber optic platform transfer mechanism to make the fiber optic platform body continuously rotate and stay along a predetermined transfer path;

[0009] S4, real-time acquisition of the fiber optic platform inertial measurement data signal and the synchronization signal, speed and position signal of the high-precision main inertial navigation system, and alignment of the fiber optic platform data with the main inertial navigation data according to the synchronization signal;

[0010] S5, using the inertial measurement data of the optical fiber platform to perform coarse alignment and obtain the initial attitude matrix of the optical fiber platform body relative to the navigation coordinate system;

[0011] S6, using the rough alignment results and the inertial measurement data of the fiber optic platform to perform navigation and solution for the fine alignment process, and update the Kalman filter state matrix in real time;

[0012] S7, judging whether the filtering time has been reached; if so, using the main inertial navigation data and navigation solution results received at the current time to calculate the Kalman filter observation quantity and observation matrix, and updating the Kalman filter equation to calculate the state quantity estimate;

[0013] S8, determine whether the alignment end time has been reached; if not, use the Kalman filter to estimate the speed and position errors to feedback and correct the system; if yes, end the alignment, use the attitude misalignment angle estimated by the Kalman filter to compensate and correct the navigation result of the fiber optic platform, and obtain the alignment result transmitted by the fiber optic platform inertial system.

[0014] Furthermore, the open-loop transfer function for applying corresponding control to the fiber platform indexing mechanism is: Where, J is the moment of inertia of the platform frame axis, G FOG (s) is the fiber optic gyro transfer function, G c (s) is the loop correction network, K p is the power level gain factor, G m (s) is the shaft end torque motor transfer function.

[0015] Furthermore, the predetermined rotation path includes: rotating the optical fiber platform 180 degrees in the positive direction around the outer ring frame axis starting from the zero position, then staying for a period of time, then rotating 180 degrees in the reverse direction around the outer ring frame axis, then staying for a period of time, and repeating this process until the alignment is completed, wherein the rotation time plus the residence time equals the total alignment time.

[0016] Furthermore, the alignment includes: the optical fiber platform collects the periodic square wave signal output by the main inertial navigation system. When the alignment process is started, the first falling edge moment when the optical fiber platform receives the synchronization signal is defined as the starting moment, and then the inertial measurement data and the main inertial navigation system speed and position information mark timestamps are aligned.

[0017] Furthermore, the step of obtaining the initial posture matrix of the optical fiber platform relative to the navigation coordinate system includes:

[0018] A relatively accurate initial attitude information is obtained by using a multi-vector attitude analytical rough alignment method based on external auxiliary information. The solution method is as follows:

[0019] Calculate the values ​​of the station system velocity vector and the navigation system velocity vector α and β:

[0020]

[0021] Where V and ΔV represent velocity and velocity increment respectively, T represents sampling period, i represents sampling time, superscript g represents projection in navigation system, k represents number of samples, t i The transformation matrix from the instantaneous stage system to the solidification stage system, Δθ is the angle increment, t i The conversion matrix from the moment navigation system to the solidified navigation system, V g is the navigation system speed, t i is the time, I is the unit matrix, G is the projection of the angular velocity of the navigation system relative to the inertial system in the navigation system, g is the projection of gravity acceleration in the navigation system, is the projection of the Earth's rotation angular velocity in the navigation system;

[0022] Find α and β at multiple moments, according to the relationship The least squares method was used to fit the

[0023] The initial posture matrix of the fiber optic platform is:

[0024]

[0025] In the formula, is the attitude transfer matrix from the stage system to the solidification stage system, which can be obtained using the gyroscope measurement value; It is the attitude transfer matrix from the initial navigation system to the solidified navigation system, which can be obtained according to the earth's rotation angular velocity and the alignment time; is the attitude transfer matrix from the initial navigation system to the current navigation system, It can be calculated based on the angular velocity caused by the linear motion of the carrier, so the calculation of the attitude matrix is ​​transformed into Calculation.

[0026] Furthermore, the state equation of the Kalman filter in S6 is: In the formula, X, are state quantity and state quantity differential respectively; A is the state matrix; ω(t) is the system noise;

[0027] The method for updating the Kalman filter state matrix in real time is:

[0028]

[0029] in, is the one-step prediction of the state at time k, φ k / k-1 is the filter state transfer matrix, is the estimated value of the state at time k-1, P k / k-1 is the variance matrix of the one-step prediction, P k-1 is the estimated variance matrix, Q k-1 is the system noise driving matrix.

[0030] Furthermore, the observation equation of the Kalman filter in S7 is:

[0031] Z=HX+v(t)

[0032] Among them, X is the state quantity, Z is the observation quantity; H is the observation matrix; ν(t) is the observation noise;

[0033] The observation matrix is:

[0034]

[0035] In the formula, δV r is the velocity error vector caused by the lever arm effect, δP r is the position error vector caused by the lever arm effect;

[0036] The measurement update calculation method of the Kalman filter in S7 is:

[0037]

[0038] in, is the optimal estimate of the state at time k, K k is the filter gain matrix, Z k is the observed quantity, R k is the measurement noise variance matrix, is the one-step prediction of the state at time k, H k is the observation matrix, P k / k-1 is the variance matrix of the one-step prediction, and I is the identity matrix.

[0039] Furthermore, in S8, the Kalman filter is used to estimate the speed and position errors to perform feedback correction on the system, and the speed correction method is:

[0040]

[0041] in, It represents the speed before and after the Kalman filter feedback compensation at time k;

[0042] The position correction method is:

[0043]

[0044] in, They represent the latitude, longitude, and altitude before and after the Kalman filter feedback compensation at time k respectively;

[0045] In S8, the calculation method of obtaining the transfer alignment result of the fiber optic platform inertial system by using the attitude misalignment angle estimated by the Kalman filter includes:

[0046] According to the calculation results of precise alignment navigation, the attitude matrix of the optical fiber platform at the end of alignment is:

[0047] The calculation method of the misalignment angle attitude compensation matrix based on the precise Kalman filter estimation value is:

[0048]

[0049] Among them, [φ x ,φ y ,φ z ] represent the estimated values ​​of attitude error angles in the x, y, and z directions respectively;

[0050] The calculation method for obtaining the transfer alignment result based on the fiber table posture matrix and the misalignment angle compensation matrix is:

[0051]

[0052] in, To compensate for the fiber optic stage posture matrix, that is, to transfer the alignment result.

[0053] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of a high-precision transfer alignment method for an active isolation optical fiber platform are implemented.

[0054] An active isolation type optical fiber platform high-precision transfer alignment device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the active isolation type optical fiber platform high-precision transfer alignment method are implemented.

[0055] The advantages of the present invention compared with the prior art are:

[0056] (1) The present invention is used in the dynamic base transfer alignment of the fiber optic platform inertial navigation system, which can replace the traditional optical aiming solution, greatly reduce the equipment support requirements and operation difficulty, and improve the user's operability.

[0057] (2) The present invention adopts a Kalman filter optimal estimation transfer alignment method based on speed + position matching, which has no special restrictions on the maneuvering conditions of the carrier, can adapt to the influence of a certain degree of carrier deformation, and has better environmental adaptability.

[0058] (3) The present invention adopts an active isolation rotation control strategy to isolate the control body from external angular motion, which can reduce the impact of the carrier angular motion on the transfer alignment and has higher accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0060] Figure 1 This is a schematic diagram of the system solution of the present invention;

[0061] Figure 2 It is the time allocation diagram of the rough alignment and the fine alignment of the present invention;

[0062] Figure 3 This is a flow chart of the precise alignment module of the present invention. DETAILED DESCRIPTION

[0063] The purpose of the present invention is to overcome the influence of factors such as low-frequency disturbance on the carrier in a dynamic environment, and at the same time, to overcome factors such as the carrier's concealment, maneuverability and carrier deformation, and to provide a high-precision transfer alignment method for an active isolated fiber optic platform to achieve the establishment of the initial attitude reference of the moving base of the fiber optic platform inertial navigation system.

[0064] In order to better understand the above technical scheme, the technical scheme of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present invention, rather than limitations on the technical scheme of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0065] The following is a further detailed description of a high-precision transfer alignment method for an active isolation optical fiber platform provided by an embodiment of the present invention in conjunction with the accompanying drawings of the specification. The specific implementation method may include:

[0066] S1: Power on and heat the fiber optic platform inertial system. After the temperature stabilizes and meets the working conditions, initialize the parameters. The platform frame is locked to zero and enters the transfer alignment process.

[0067] S2: According to the gyroscope output signal of the fiber optic platform system, the angular velocity information sensed by the platform body is calculated, and the corresponding control torque is applied to the platform indexing mechanism to keep the platform body stable relative to the inertial space;

[0068] S3: Apply control instructions to the fiber optic platform transfer mechanism to make the platform continuously rotate and stop according to the predetermined transfer path to improve the observability of the system;

[0069] S4: collects the inertial measurement data signals of the fiber optic platform and the synchronization signals, speed and position signals of the high-precision main inertial navigation system in real time, and aligns the fiber optic platform data with the main inertial navigation data according to the synchronization signals;

[0070] S5: Use the fiber optic platform inertial measurement data to perform coarse alignment and roughly obtain the initial attitude matrix of the platform body relative to the navigation coordinate system;

[0071] S6: Use the rough alignment results and the fiber optic platform inertial measurement data to perform navigation and solution for the fine alignment process, and update the Kalman filter state matrix in real time;

[0072] S7: Determine whether the filtering time has been reached. If so, use the main inertial navigation data and navigation solution results received at the current time to calculate the Kalman filter observation quantity and observation matrix, update the Kalman filter equation, and calculate the state quantity estimate;

[0073] S8: Determine whether the alignment end time has been reached. If not, use the Kalman filter to estimate the speed and position errors to provide feedback correction to the system. If yes, end the alignment, use the attitude misalignment angle estimated by the Kalman filter to compensate and correct the platform navigation result, and obtain the alignment result transmitted by the fiber optic platform system.

[0074] Furthermore, the open-loop transfer function of the control loop in S2 that enables the platform to maintain inertial space stability is:

[0075]

[0076] Where, J is the moment of inertia of the platform frame axis, G FOG (s) is the fiber optic gyro transfer function, G c (s) is the loop correction network, K p is the power level gain factor, G m (s) is the shaft end torque motor transfer function.

[0077] In a possible implementation, in order to increase the observability of the system in S3, the platform is rotated 180 degrees around the celestial axis during the alignment process, and the predetermined transfer path is as follows:

[0078] Serial number Outer ring angle (°) Inner ring angle (°) Table angle (°) 0 Forward rotation 180 0 0 1 180 0 0 2 Reverse rotation 180 0 0 3 … … …

[0079] As shown in the table above, the fiber optic platform is rotated 180 degrees from the zero position around the outer ring frame axis in the positive direction, then stays for a period of time, and then rotated 180 degrees in the opposite direction around the outer ring frame axis, and then stays for a period of time. This process is repeated until the alignment is completed, where the rotation time plus the dwell time equals the total alignment time.

[0080] The transfer alignment process includes multiple dwelling positions and multiple rotation processes. The platform body starts from the zero position and rotates 180° around the outer ring axis each time. After reaching each position, the platform body is in a spatially stable state and stays for a period of time.

[0081] Further, the main inertial navigation output synchronization signal is used in S4 to perform time synchronization and data alignment between the main and sub inertial navigation systems, which specifically includes:

[0082] The fiber optic platform collects the periodic square wave signal output by the main inertial navigation system. When the alignment process starts, the moment when the platform receives the first falling edge of the synchronization signal is defined as the starting moment. After that, the inertial measurement data and the timestamps of the main inertial navigation system’s velocity and position information are aligned.

[0083] In a possible implementation, the step of obtaining a rough alignment attitude matrix using the inertial measurement data of the optical fiber platform in S5 specifically includes:

[0084] A relatively accurate initial attitude information is obtained by using a multi-vector attitude analytical rough alignment method based on external auxiliary information. The solution method is as follows:

[0085] Calculate the values ​​of the station system velocity vector and the navigation system velocity vector α and β:

[0086]

[0087] Where V and ΔV represent velocity and velocity increment respectively, T represents sampling period, subscript i represents the i-th sampling moment, superscript g represents the projection in the navigation system, k represents the number of samples, t i The transformation matrix from the instantaneous stage system to the solidification stage system, Δθ is the angle increment, t i The conversion matrix from the moment navigation system to the solidified navigation system, V g is the navigation system speed, t i is the time, I is the unit matrix, G is the projection of the angular velocity of the navigation system relative to the inertial system in the navigation system, g is the projection of gravity acceleration in the navigation system, is the projection of the Earth's rotation angular velocity in the navigation system;

[0088] Find α and β at multiple moments, according to the relationship The least squares method is used to fit the result;

[0089] The method to solve the initial posture matrix of the platform is:

[0090]

[0091] In the formula, is the attitude transfer matrix from the stage system to the solidification stage system, which can be obtained using the gyroscope measurement value; It is the attitude transfer matrix from the initial navigation system to the solidified navigation system, which can be obtained according to the earth's rotation angular velocity and the alignment time; is the attitude transfer matrix from the initial navigation system to the current navigation system, It can be calculated based on the angular velocity caused by the linear motion of the carrier, so the calculation of the attitude matrix can be converted into Calculation.

[0092] In a possible implementation, the state equation of the precise Kalman filter in S6 is:

[0093]

[0094] Where X, —state quantity, state quantity differential; A—state matrix; ω(t)-system noise.

[0095] Further, the precise Kalman filter state update formula in S6 is:

[0096]

[0097] in, is the one-step prediction of the state at time k, φ k / k-1 is the filter state transfer matrix, is the estimated value of the state at time k-1, P k / k-1 is the variance matrix of the one-step prediction, P k-1 is the estimated variance matrix, Q k-1 is the system noise driving matrix.

[0098] In a possible implementation, the observation equation of the precise Kalman filter in S7 is:

[0099] Z=HX+v(t)

[0100] Where Z-observation quantity; X-state quantity; H-observation matrix; ν(t)-observation noise;

[0101] The observation matrix can be expressed as:

[0102] In the formula, δVr is the velocity error vector caused by the lever arm effect, δP r is the position error vector caused by the lever arm effect;

[0103] In a possible implementation, the calculation formula for accurately aligning the Kalman filter measurement update in S7 is:

[0104]

[0105] in, is the optimal estimate of the state at time k, K k is the filter gain matrix, Z k is the observed quantity, R k is the measurement noise variance matrix, H k is the observation matrix and I is the identity matrix.

[0106] In a possible implementation, the Kalman filter is used in S8 to estimate the speed and position errors and perform feedback correction on the system. Specifically, the speed correction formula is:

[0107]

[0108] in, It represents the speed before and after the Kalman filter feedback compensation at time k;

[0109] The position correction formula is:

[0110]

[0111] in, They represent the latitude, longitude, and altitude before and after the Kalman filter feedback compensation at time k respectively;

[0112] In a possible implementation, the calculation method for obtaining the transmission alignment result of the optical fiber platform system using the attitude misalignment angle estimated by the Kalman filter in S8 is as follows:

[0113] According to the calculation results of precise alignment navigation, the platform attitude matrix at the end of alignment is obtained as follows:

[0114] The calculation method of the misalignment angle attitude compensation matrix based on the precise Kalman filter estimation value is:

[0115]

[0116] Among them, [φ x ,φ y ,φ z ] represent the estimated values ​​of attitude error angles in the x, y, and z directions respectively;

[0117] The calculation method of the transfer alignment result is obtained according to the stage attitude matrix and the misalignment angle compensation matrix:

[0118]

[0119] in, To compensate the background body pose matrix, the alignment result is transferred.

[0120] In the solution provided in the embodiment of the present invention, the transfer alignment solution adopts the Kalman filter optimal estimation method based on "speed + position" matching to estimate the attitude misalignment angle of the fiber optic platform, that is, the speed and position errors output by the main and sub-inertial navigation are used as observation quantities, and the error parameters are estimated through the Kalman filter. At the same time, the control body is rotated around the celestial axis to improve the observability of the Kalman filter, so as to achieve high-precision transfer alignment in a dynamic environment. The overall solution principle block diagram is shown in the figure. Figure 1 shown.

[0121] In this embodiment, a high-precision transfer alignment method for an active isolation optical fiber platform is provided, and the implementation steps include:

[0122] (1) Platform power-on heating

[0123] The fiber optic platform inertial system is powered on and heated. After the temperature stabilizes and meets the working conditions, the parameters are initialized and the platform frame is locked to zero to enter the transfer alignment process.

[0124] (2) Table rotation control

[0125] Control instructions are applied to the fiber optic platform indexing mechanism to make the platform body rotate and stay continuously according to the predetermined indexing path. The indexing process is shown in the following table, which includes 12 dwell positions and 12 indexing processes. The platform body rotates 180° forward and reverse around the outer ring axis each time from the zero position, for a total of 12 times, with an angular rate of 15° / s. After reaching each position, the platform body is in a spatially stable state and stays for a period of time. The total time of the entire alignment process is 15 minutes.

[0126] Serial number Outer ring angle (°) Inner ring angle (°) Table angle (°) 0 Forward rotation 180 0 0 1 180 0 0 2 Reverse rotation 180 0 0 3 0 0 0 4 … … …

[0127] (3) Main and sub-inertial navigation data acquisition

[0128] The fiber-optic platform inertial measurement data signals and the synchronization signals, speed and position signals of the high-precision main inertial navigation system are collected in real time, and the fiber-optic platform data are aligned with the main inertial navigation data according to the synchronization signals.

[0129] (4) Rough alignment calculation

[0130] The sampling time allocation of the coarse and fine alignment process is as follows Figure 2The rough alignment calculation is performed using the inertial measurement data of the fiber optic platform and the main inertial navigation sampling data during the rough alignment process to roughly obtain the initial attitude matrix of the platform body relative to the navigation coordinate system.

[0131] (5) Precision Alignment Calculation

[0132] The fine alignment process flow chart is as follows Figure 3 The rough alignment results and the inertial measurement data of the fiber optic platform are used to perform navigation and calculation in the fine alignment process, and the Kalman filter state matrix is ​​updated in real time.

[0133] The state variables selected in the precise Kalman filter are:

[0134] X=[Z gx ,Z gy ,Z gz ,φ x ,φ y ,φ z ,Z ax ,Z ay ,Z az ,δV E ,δV N ,δV U ,δL,δλ,δh] T

[0135] Among them, Z gx , Z gy , Z gz Indicates the gyroscope zero bias, Z ax , Z ay , Z az represents the accelerometer zero bias, φ x ,φ y ,φ z Indicates the attitude misalignment angle, δV E , δV N , δV U represents the speed error, δL, δλ, δh represent the position error;

[0136] The state matrix calculation formula is as follows:

[0137]

[0138] in,

[0139]

[0140] Among them, ω ie is the angular velocity of the Earth's rotation, [V E 、V N 、V U ] are the eastward, northward and celestial velocities, R Mis the principal radius of curvature of the meridian, R N is the main curvature radius of the y-axis, h is the height, L is the latitude,

[0141] [f E 、f N 、f U ] is a comparison of the east, north and sky directions.

[0142] The state transfer matrix is ​​calculated according to the state matrix. The calculation formula is:

[0143]

[0144] Among them, A(t k ) is t k The state matrix at each moment, T is the sampling period, and I is the unit matrix.

[0145] Determine whether the filtering time has been reached. If so, use the main inertial navigation data and navigation solution results received at the current time to calculate the Kalman filter observations and observation matrix. The observations selected for the precise Kalman filter are:

[0146] Z=[δV E ,δV N ,δV U ,δL,δλ,δh] T

[0147] The calculation formula of the observed quantity is as follows:

[0148]

[0149] Where V is the velocity vector, [L, λ, h] is the latitude, longitude, and altitude, the subscript s represents the fiber optic platform, and m represents the main inertial navigation.

[0150] The calculation formula of the observation matrix is ​​as follows:

[0151]

[0152] In the formula, δV r is the velocity error vector caused by the lever arm effect, δP r is the position error vector caused by the lever arm effect;

[0153] The Kalman filter equation is updated and the estimated value of the state quantity is calculated.

[0154] (6) Estimation error compensation and correction, calculation of alignment results

[0155] Determine whether the alignment end time has been reached. If not, use the Kalman filter to estimate the speed and position errors to perform feedback correction on the system. The calculation formula is as follows:

[0156]

[0157] in, is the estimated value of the state quantity.

[0158] If the alignment end time is reached, the alignment is terminated, and the attitude misalignment angle estimated by the Kalman filter is used to compensate and correct the platform navigation result, and the alignment result transmitted by the optical fiber platform system is calculated. The calculation formula is as follows:

[0159] According to the calculation results of precise alignment navigation, the platform attitude matrix at the end of alignment is obtained as follows:

[0160] The calculation method of the misalignment angle attitude compensation matrix based on the precise Kalman filter estimation value is:

[0161]

[0162] in, Respectively represent the estimated values ​​of attitude error angles in the x, y, and z directions;

[0163] The calculation formula for the transfer alignment result is obtained based on the stage attitude matrix and the misalignment angle compensation matrix:

[0164]

[0165] in, To compensate the background body pose matrix, the alignment result is transferred.

[0166] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0167] The present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and when the computer instructions are executed on a computer, the computer executes Figure 1 The method described.

[0168] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0169] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0170] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0171] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0172] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0173] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A high-precision transfer alignment method for an active isolation optical fiber platform, characterized in that: include: S1, power on and heat the fiber optic platform inertial system, initialize parameters after the temperature stabilizes and meets the working conditions, and enter the transfer alignment process after the fiber optic platform frame is locked to zero; S2, according to the gyroscope output signal of the fiber optic platform inertial system, calculate the angular velocity information sensed by the fiber optic platform body, and exert corresponding control on the fiber optic platform indexing mechanism to keep the fiber optic platform body stable relative to the inertial space; S3, controlling the fiber optic platform transfer mechanism to make the fiber optic platform body continuously rotate and stay along a predetermined transfer path; S4, real-time acquisition of the fiber optic platform inertial measurement data signal and the synchronization signal, speed and position signal of the high-precision main inertial navigation system, and alignment of the fiber optic platform data with the main inertial navigation data according to the synchronization signal; S5, using the inertial measurement data of the optical fiber platform to perform coarse alignment and obtain the initial attitude matrix of the optical fiber platform body relative to the navigation coordinate system; S6, using the rough alignment results and the inertial measurement data of the fiber optic platform to perform navigation and solution for the fine alignment process, and update the Kalman filter state matrix in real time; S7, judging whether the filtering time has been reached; If yes, the Kalman filter observation quantity and observation matrix are calculated using the main inertial navigation data and navigation solution results received at the current moment, and the Kalman filter equation is updated to calculate the estimated value of the state quantity; S8, determining whether the alignment end time has been reached; If not, the Kalman filter is used to estimate the speed and position errors to feedback and correct the system; if yes, the alignment is terminated, and the attitude misalignment angle estimated by the Kalman filter is used to compensate and correct the navigation result of the fiber optic platform body to obtain the alignment result transferred by the fiber optic platform inertial system.

2. The high-precision transfer alignment method of an active isolation optical fiber platform according to claim 1, characterized in that: The open-loop transfer function for applying corresponding control to the fiber platform indexing mechanism is: Where, J is the moment of inertia of the platform frame axis, G FOG (s) is the fiber optic gyro transfer function, G c (s) is the loop correction network, K p is the power level gain factor, G m (s) is the shaft end torque motor transfer function.

3. The high-precision transfer alignment method of an active isolation optical fiber platform according to claim 1, characterized in that: The predetermined rotation path includes: rotating the optical fiber platform 180 degrees in the positive direction around the outer ring frame axis from the zero position, then staying for a period of time, then rotating 180 degrees in the reverse direction around the outer ring frame axis, then staying for a period of time, and repeating this process until the alignment is completed, wherein the rotation time plus the stay time equals the total alignment time.

4. The high-precision transfer alignment method of an active isolation optical fiber platform according to claim 1, characterized in that: The alignment includes: the optical fiber platform collects the periodic square wave signal output by the main inertial navigation system. When the alignment process is started, the first falling edge moment of the synchronization signal received by the optical fiber platform is defined as the starting moment, and then the inertial measurement data and the main inertial navigation system speed and position information mark timestamps are aligned.

5. The high-precision transfer alignment method of an active isolation optical fiber platform according to claim 1, characterized in that: The step of obtaining the initial posture matrix of the optical fiber platform relative to the navigation coordinate system includes: A relatively accurate initial attitude information is obtained by using a multi-vector attitude analytical rough alignment method based on external auxiliary information. The solution method is as follows: Calculate the values ​​of the station system velocity vector and the navigation system velocity vector α and β: Where V and ΔV represent velocity and velocity increment respectively, T represents sampling period, i represents sampling time, superscript g represents projection in navigation system, k represents number of samples, t i The transformation matrix from the instantaneous stage system to the solidification stage system, Δθ is the angle increment, t i The conversion matrix from the moment navigation system to the solidified navigation system, V g is the navigation system speed, t i is the time, I is the unit matrix, G is the projection of the angular velocity of the navigation system relative to the inertial system in the navigation system, g is the projection of gravity acceleration in the navigation system, is the projection of the Earth's rotation angular velocity in the navigation system; Find α and β at multiple moments, according to the relationship The least squares method was used to fit the The initial posture matrix of the fiber optic platform is: In the formula, is the attitude transfer matrix from the stage system to the solidification stage system, which can be obtained using the gyroscope measurement value; It is the attitude transfer matrix from the initial navigation system to the solidified navigation system, which can be obtained according to the earth's rotation angular velocity and the alignment time; is the attitude transfer matrix from the initial navigation system to the current navigation system, It can be calculated based on the angular velocity caused by the linear motion of the carrier, so the calculation of the attitude matrix is ​​transformed into Calculation.

6. The high-precision transfer alignment method of an active isolation optical fiber platform according to claim 1, characterized in that: The state equation of the Kalman filter in S6 is: In the formula, X, are state quantity and state quantity differential respectively; A is the state matrix; ω(t) is the system noise; The method for updating the Kalman filter state matrix in real time is: in, is the one-step prediction of the state at time k, φ k / k-1 is the filter state transfer matrix, is the estimated value of the state at time k-1, P k / k-1 is the variance matrix of the one-step prediction, P k-1 is the estimated variance matrix, Q k-1 is the system noise driving matrix.

7. The high-precision transfer alignment method of an active isolation optical fiber platform according to claim 1, characterized in that: The observation equation of the Kalman filter in S7 is: Z=HX+v(t) Among them, X is the state quantity, Z is the observation quantity; H is the observation matrix; ν(t) is the observation noise; The observation matrix is: In the formula, δV r is the velocity error vector caused by the lever arm effect, δP r is the position error vector caused by the lever arm effect; The measurement update calculation method of the Kalman filter in S7 is: in, is the optimal estimate of the state at time k, K k is the filter gain matrix, Z k is the observed quantity, R k is the measurement noise variance matrix, is the one-step prediction of the state at time k, H k is the observation matrix, P k / k-1 is the variance matrix of one-step prediction, and I is the identity matrix.

8. The high-precision transfer alignment method of an active isolation optical fiber platform according to claim 1, characterized in that: In S8, the Kalman filter is used to estimate the speed and position errors to perform feedback correction on the system. The speed correction method is: in, It represents the speed before and after the Kalman filter feedback compensation at time k; The position correction method is: in, They represent the latitude, longitude, and altitude before and after the Kalman filter feedback compensation at time k respectively; In S8, the calculation method of obtaining the transfer alignment result of the fiber optic platform inertial system by using the attitude misalignment angle estimated by the Kalman filter includes: According to the calculation results of precise alignment navigation, the attitude matrix of the optical fiber platform at the end of alignment is: The calculation method of the misalignment angle attitude compensation matrix based on the precise Kalman filter estimation value is: Among them, [φ x ,φ y ,φ z ] represent the estimated values ​​of attitude error angles in the x, y, and z directions respectively; The calculation method for obtaining the transfer alignment result based on the fiber table posture matrix and the misalignment angle compensation matrix is: in, To compensate for the fiber optic stage posture matrix, that is, to transfer the alignment result.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

10. An active isolation type fiber optic platform high-precision transfer alignment device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

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