A laser inertial navigation single-point correction method for suppressing navigation earth oscillation error

Abstract

This application discloses a single-point correction method for laser inertial navigation to suppress navigation Earth oscillation errors, relating to the field of inertial navigation. The method includes: acquiring external single-point position reference information and recording the current navigation time T of the laser inertial navigation system; comparing the current calculated position of the laser inertial navigation system with the external reference information to obtain the latitude error δL(T) of the laser inertial navigation position; calculating the gyroscope zero-bias error using a correction parameter calculation formula, and using the eastward gyroscope zero-bias error ε... E Northward gyroscope zero bias error ε N And the zero bias error ε of the gyroscope U The system corrects the gyro angular motion data of the navigation system, updates the laser inertial navigation calculations, and readjusts the system position error while suppressing the Earth oscillation error. The latitude and longitude of the system installation position calculated by the current laser inertial navigation system are assigned with the latitude and longitude of external reference information to achieve the readjustment of the system position error.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inertial navigation, in particular to a laser inertial navigation single-point correction method for suppressing navigation earth oscillation error. BACKGROUND

[0002] The laser gyro inertial navigation system is referred to as a laser inertial navigation system. A single-point correction technology applied to the laser inertial navigation system takes the suppression of latitude oscillation error as the correction criterion, and can realize the suppression of inertial navigation parameter earth oscillation error based on single-point reference position information.

[0003] In the field of high-precision inertial navigation, the laser inertial navigation system usually adopts a double-axis rotation modulation automatic compensation technology to substantially improve the navigation precision of the system with limited increase in system cost. The laser inertial navigation system based on the rotation modulation technology can realize automatic compensation of all inertial device deterministic errors. However, due to the influence of factors such as gyro angle random walk and earth rotation coupling error, the laser inertial navigation error still has the problems of time divergence error and earth oscillation error. The existing technical solutions can only re-adjust the position and cannot suppress the time divergence error and earth oscillation error caused by the gyro angle random walk and earth rotation coupling, resulting in defects in use. SUMMARY

[0004] The purpose of the present application is to provide a single-point correction method which can not only re-adjust the position error of the laser inertial navigation system, but also suppress the navigation earth oscillation error.

[0005] The technical solution of the present application is to provide a laser inertial navigation single-point correction method for suppressing navigation earth oscillation error, which comprises the following steps:

[0006] S1. Obtain external reference information of the current carrier coordinate, including geographic latitude L and geographic longitude λ, and record the navigation time T of the current laser inertial navigation system;

[0007] S2. Subtract the latitude of the system installation position obtained by solving the current laser inertial navigation system from the geographic latitude L in the external reference information to obtain the latitude error δL(T) of the laser inertial navigation position;

[0008] S3. Calculate the gyro zero error using the correction parameter calculation formula:

[0009]

[0010] wherein ε E represents the east gyro zero error, ε N represents the north gyro zero error, and ε U represents the sky gyro zero error, and ω ie represents the earth rotation angular velocity.

[0011] Use east gyro zero error ε E , north gyro zero error ε N And the sky gyro zero error ε U Correct the gyro angle movement data of the navigation system, complete the correction of the gyro;

[0012] S4, the latitude and longitude of the system installation position obtained by the current laser inertial navigation system are valued with the latitude and longitude of the external reference information, and the influence of the pre-calibration running error is eliminated.

[0013] In any of the above technical solutions, further, the correction parameter calculation formula in step S3 is obtained based on the reconstructed latitude error δL(T), and the general equation of the laser inertial navigation latitude earth oscillation term error is:

[0014]

[0015] Where, φ E0 is the east attitude misalignment angle, φ N0 is the north attitude misalignment angle, φ U0 is the sky attitude misalignment angle, and δL0(T) is the initial latitude error.

[0016] In any of the above technical solutions, further, in the general equation of the laser inertial navigation latitude earth oscillation term error, the terms related to φ E0 , φ N0 , φ U0 , δ L0 (T) and ε E are ignored, and the amplitude of the latitude oscillation is focused on, and the following is reconstructed:

[0017]

[0018] In any of the above technical solutions, further, in the damping working state of the laser inertial navigation system, the latitude is mainly affected by the earth oscillation error with the period of the earth rotation.

[0019] In any of the above technical solutions, further, the correction parameter calculation formula in step S3 does not change the slope of the longitude error divergence with time, and the error term δλ(T) of the longitude error divergence with time is:

[0020] δλ(T)=(ε N cos L+ε U sinL)*T.

[0021] In any of the above technical solutions, further, the correction parameters ε N and ε U satisfy: 0=ε N cosL+εU sinL.

[0022] In any of the technical solutions above, further, the process of correcting the gyro angular motion data of the navigation system comprises: extracting the gyro angular motion data in three directions and subtracting the gyro zero offset error in the corresponding direction respectively, and using the calculated motion data to cover the current gyro angular motion data.

[0023] The beneficial effects of the present application are:

[0024] In the technical solution of the present application, based on the reconstructed latitude position error equation of the laser inertial navigation system, an error correction criterion for suppressing the navigation earth oscillation is established. By using the correction criterion, the system position error can be re-adjusted, and the earth oscillation error caused by the gyro angular random walk and the coupling of the earth rotation can be suppressed, thereby improving the navigation performance of the laser inertial navigation system during long-time navigation. BRIEF DESCRIPTION OF DRAWINGS

[0025] The advantages of the above and additional aspects of the present application will become apparent and easily understood in conjunction with the description of embodiments with reference to the following drawings, in which:

[0026] Figure 1 is a schematic flow chart of a laser inertial navigation single-point correction method for suppressing navigation earth oscillation error according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0028] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0029] As Figure 1 shown, the present embodiment provides a laser inertial navigation single-point correction method for suppressing navigation earth oscillation error, which comprises:

[0030] S1, obtaining external single-point position reference information including geographic latitude L and geographic longitude λ, and recording the current laser inertial navigation system navigation time T.

[0031] S2, subtracting the latitude of the system installation position calculated by the current laser inertial navigation system from the geographic latitude L in the external reference information to obtain the laser inertial navigation position error δL(T).

[0032] Specifically, the laser inertial navigation position error mainly includes oscillation type error and linear divergence error over time, wherein the oscillation type error can be divided into Schuler oscillation and earth oscillation according to the oscillation period.

[0033] The longitude error is mainly linear divergence error over time, the latitude error is mainly oscillation type error, and the Schuler oscillation of the laser inertial navigation system in the damping working state is small, and is mainly affected by the earth oscillation error with the earth rotation period as the period.

[0034] S3, calculating the gyro zero bias error using the correction parameter calculation formula:

[0035]

[0036] wherein, ε E represents the east gyro zero bias error, ε N represents the north gyro zero bias error, and ε U represents the sky gyro zero bias error, ω ie represents the earth rotation angular velocity.

[0037] The east gyro zero bias error ε E , the north gyro zero bias error ε N and the sky gyro zero bias error ε U are used to correct the gyro angular motion data of the navigation system, and the correction of the gyro is completed.

[0038] The correction parameter calculation formula is obtained based on the reconstructed latitude error δL(T), and the general equation of the laser inertial navigation latitude earth oscillation term error is:

[0039]

[0040] wherein, φ E0 is the east attitude misalignment angle, φ N0 is the north attitude misalignment angle, φ U0 is the sky attitude misalignment angle, and δL0(T) is the initial latitude error.

[0041] Ignoring the related terms of φ E0 , φ N0 , φ U0 , δ L0 (T) and ε E , and focusing on the latitude oscillation amplitude, the following is obtained by reconstruction:

[0042]

[0043] In addition, in terms of longitude, the correction parameter calculation formula does not change the slope of the longitude error divergence over time, and the error term δλ(T) of the longitude error divergence over time is:

[0044] δλ(T)=(ε Ncos L+ε U sin L)*T.

[0045] correction parameter ε N and ε U satisfies:

[0046] 0=ε N cos L+ε U sin L.

[0047] Specifically, the longitude error mainly in time linear divergence error and the latitude error mainly in earth oscillation error are directly related to the gyro zero bias error, the principle of gyro zero bias solution for point position correction is established: after error re-adjustment, the system longitude divergence error rule remains unchanged, and the system latitude earth oscillation error is as small as possible, and the relationship is obtained:

[0048]

[0049] The relationship can be obtained after the correction parameter calculation formula in the above step S3 is arranged.

[0050] After obtaining the gyro zero bias error in three directions, the gyro angular motion data in three directions are extracted and subtracted by the gyro zero bias error in the corresponding direction, and the calculated motion data is used to cover the current gyro angular motion data, and the gyro correction is completed.

[0051] S4, the latitude and longitude of the system installation position calculated by the current laser inertial navigation system are valued by the latitude and longitude of the external reference information, and the influence of the error in the running before calibration is eliminated.

[0052] Specifically, the laser inertial navigation single-point correction method provided by the application corrects the gyro angular motion data by one sampling of the true value, completes the gyro correction, that is, completes the correction of the laser inertial navigation system, and at this time, the true value sampled is used to cover the current system solution value; continue to solve based on the true position, and ensure the solution accuracy of the laser inertial navigation system.

[0053] In summary, the application provides a laser inertial navigation single-point correction method for suppressing navigation earth oscillation error, comprising:

[0054] S1, obtaining external single-point position reference information, and recording the navigation time T of the current laser inertial navigation system.

[0055] S2, the latitude of the system installation solution position obtained by the current laser inertial navigation system is subtracted from the geographic latitude L in the external reference information, and the latitude error δL(T) of the laser inertial navigation position is obtained.

[0056] S3, the gyro zero bias error is calculated using the correction parameter calculation formula:

[0057]

[0058] Using east gyro zero bias error ε E , north gyro zero bias error ε N and sky gyro zero bias error ε U Correct the gyro angular motion data of the navigation system, update the calculation of the laser inertial navigation.

[0059] S4, the latitude and longitude of the system installation position obtained by the current laser inertial navigation system are valued with the latitude and longitude of the external reference information, and the position error of the system is re-adjusted.

[0060] The steps in the application can be adjusted, combined and deleted according to actual needs.

[0061] Although the application is disclosed in detail with reference to the accompanying drawings, it should be understood that the description is only exemplary and is not intended to limit the application of the application. The scope of protection of the application is defined by the appended claims, and can include various modifications, improvements and equivalent solutions made to the application without departing from the scope and spirit of the application.

Claims

1. A laser inertial navigation single-point correction method for suppressing navigation earth oscillation error, characterized in that, The method comprises: S1, obtaining external reference information of current carrier coordinates, including geographic latitude L and geographic longitude λ, and recording current laser inertial navigation system navigation time T; S2, subtracting the latitude of the system installation position calculated by the current laser inertial navigation system from the geographic latitude L in the external reference information to obtain the latitude error δL(T) of the laser inertial navigation position; S3, calculating the gyro zero offset error using a correction parameter calculation formula: wherein ε E represents the east gyro zero bias error, ε N represents the north gyro zero bias error, ε U represents the sky gyro zero bias error, ω ie represents the earth rotation angular velocity; using east gyro zero error ε E , north gyro zero error ε N and sky gyro zero error ε U correcting the gyro angular motion data of the navigation system, completing the correction of the gyro S4, assigning the latitude and longitude of the system installation position calculated by the current laser inertial navigation system with the latitude and longitude of the external reference information to eliminate the influence of the running error before calibration; The correction parameter calculation formula in step S3 is obtained based on the reconstructed latitude error δL(T), and the general equation of the laser inertial latitude earth oscillation error is: where φ E0 is the east attitude misalignment angle, φ N0 is the north attitude misalignment angle, and φ U0 is the skyward attitude misalignment angle, and δL0(T) is the initial latitude error. In the general equation of the laser inertial navigation latitude earth oscillation term error, φ E0 , φ N0 , φ U0 , δL0(T) and ε E related terms are ignored, and the latitude oscillation amplitude is focused on, and the following is obtained by reconstruction:

2. The laser inertial navigation single point correction method for suppressing navigation earth oscillation error according to claim 1, wherein, In the damping working state of the laser inertial navigation system, the latitude is mainly affected by the earth oscillation error with a period of earth rotation.

3. The laser inertial navigation single point correction method for suppressing navigation earth oscillation error according to claim 1, wherein, The correction parameter calculation formula in step S3 does not change the slope of the longitude error divergence with time, and the error term δλ(T) of the longitude error divergence with time is: delta lambda (T) = (epsilon N cos L + epsilon U sin L) * T.

4. The laser inertial navigation single point correction method for suppressing navigation earth oscillation error according to claim 3, wherein, Correction parameter ε N and ε U satisfies: 0 = ε N cos L + ε U sin L.

5. The method of claim 1, wherein the laser inertial navigation single point correction method for suppressing navigation earth oscillation error is characterized by, The process of correcting the gyro angular motion data of the navigation system comprises: extracting the angular motion data of the gyro in three directions and subtracting the gyro zero offset error in the corresponding direction respectively, and using the calculated motion data to cover the current gyro angular motion data.

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