CN-117589194-B - Small-angle calibration method and device for inertial navigation system and storage medium

CN117589194BCN 117589194 BCN117589194 BCN 117589194BCN-117589194-B

Abstract

The application relates to the technical field of navigation, in particular to a small-angle calibration method and device for an inertial navigation system and a storage medium. According to the application, firstly, the accelerometer and the gyroscope in the inertial navigation system are calibrated by adopting a multi-position calibration method, the calibration can be completed in a shorter period, a calibration result with lower precision is obtained, and then the gyroscope installation error calibration and the scale factor error calibration are performed by using a small angular velocity rotation mode, so that the calibration precision of the gyroscope is further improved, the requirement of automatic calibration requiring statistical rotation is met, and finally, the inertial navigation system is subjected to system-level calibration to obtain a high-precision calibration result, thereby solving the technical problem that the calibration method in the prior art cannot realize the high-precision calibration in a shorter period.

Inventors

CHENG RICHENG
LI JIANLING
DU YONG
XIONG HAIHONG
WU XINWEI

Assignees

中船星惯科技(武汉)有限公司

Dates

Publication Date: 20260508
Application Date: 20231109

Claims (7)

1. The small-angle calibration method of the inertial navigation system is characterized by comprising the following steps of: S1, performing multi-position calibration on an accelerometer in an inertial navigation system to obtain a coarse calibration result of the accelerometer; s2, performing multi-position calibration on the gyroscope in the inertial navigation system to obtain a coarse calibration result of the gyroscope; S3, calibrating the installation error and the scale factor error of the gyroscope by using a small angular velocity rotation mode, and improving the calibration precision of the gyroscope; S4, performing system-level calibration on the inertial navigation system to obtain a high-precision calibration result; the process for calibrating the accelerometer at multiple positions comprises the following steps: S11, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of the turntable, rotating the middle frame shaft, taking a plurality of first angles in the rotating process, and collecting the output of the accelerometer and the output of the turntable at each first angle; s12, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of the turntable, rotating the outer frame shaft to a first preset angle, rotating the middle frame shaft, taking a plurality of first angles in the rotating process, and collecting the output of the accelerometer and the output of the turntable at each first angle; s13, substituting the output of the accelerometer and the output of the turntable into an accelerometer installation error model, and calculating calibration parameters of the accelerometer to obtain zero offset, scale factors and installation errors of the accelerometer; the process for calibrating the gyroscope at multiple positions comprises the following steps: S21, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of the turntable, rotating the middle frame shaft, taking a plurality of second angles in the rotating process, and collecting the output of the gyroscope and the output of the turntable at each second angle; S22, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of the turntable, rotating the outer frame shaft to a second preset angle, rotating the middle frame shaft, taking a plurality of second angles in the rotating process, and collecting the output of the gyroscope and the output of the turntable at each second angle; s23, substituting the output of the gyroscope and the output of the turntable into a gyroscope installation error model, and calculating calibration parameters of the gyroscope to obtain zero offset, scale factors and installation errors of the gyroscope; The expression of the gyroscope installation error model is as follows: ; Wherein, the Calibration parameters of the gyroscope; Is that , The rotation angular velocity of the earth, L is the latitude of the calibrated place, 、 And The angles of the outer frame shaft, the middle frame shaft and the inner frame shaft are respectively; is the output of the gyroscope.
2. The inertial navigation system small angle calibration method of claim 1, wherein the expression of the accelerometer installation error model is as follows: ; Wherein, the Calibration parameters of the accelerometer; Is that , And The angles of the middle frame shaft and the inner frame shaft are respectively; Is the output of the accelerometer.
3. The inertial navigation system small angle calibration method of claim 1, wherein the process of using small angular velocity rotation to perform the gyroscope installation error calibration and the scale factor error calibration comprises: S31, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of a turntable, rotating the outer frame shaft at a preset angular speed, recording the output of the turntable and the output of a gyroscope when the outer frame shaft rotates from a first position to a second position, zeroing the outer frame shaft, the middle frame shaft and the inner frame shaft, reversely rotating the outer frame shaft at the preset angular speed, and recording the output of the turntable and the output of the gyroscope when the outer frame shaft rotates from the second position to the first position; S32, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of a turntable, rotating the middle frame shaft at a preset angular speed, recording the output of the turntable and the output of a gyroscope when the middle frame shaft rotates from a third position to a fourth position, zeroing the outer frame shaft, the middle frame shaft and the inner frame shaft, reversely rotating the middle frame shaft at the preset angular speed, and recording the output of the turntable and the output of the gyroscope when the middle frame shaft rotates from the fourth position to the third position; S33, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of a turntable, rotating the inner frame shaft at a preset angular speed, recording the output of the turntable and the output of a gyroscope when the inner frame shaft rotates from a fifth position to a sixth position, zeroing the outer frame shaft, the middle frame shaft and the inner frame shaft, reversely rotating the inner frame shaft at the preset angular speed, and recording the output of the turntable and the output of the gyroscope when the inner frame shaft rotates from the sixth position to the fifth position; s34, substituting the output of the turntable and the output of the gyroscope into a gyroscope scale factor and installation error array calculation formula to obtain the scale factor and the installation error array of the gyroscope.
4. A method for small angle calibration of an inertial navigation system according to claim 3, wherein the expression of the gyroscope scale factor and installation error matrix calculation formula is as follows: ; Wherein, the = , For the output of the gyroscope when rotating the outer frame shaft, the middle frame shaft and the inner frame shaft, And outputting the gyroscope when the outer frame shaft, the middle frame shaft and the inner frame shaft are reversely rotated.
5. The inertial navigation system small angle calibration method of claim 1, wherein the system level calibration process comprises: S41, respectively establishing a scale factor error and an installation error model of the accelerometer and the gyroscope; S42, establishing an error equation of the inertial navigation system; s43, calculating position errors, speed errors, attitude errors, scale factor errors and installation errors to be filter state quantities through the inertial navigation system, and establishing a state equation; S44, taking the difference value between the position information calculated by the inertial navigation system and the position information provided by the GPS as the quantity measurement of a filter, and establishing a measurement equation; S45, carrying out one-step prediction on the basis of the step S43; s46, correcting the one-step prediction result according to the measurement result of the step S44 to obtain an optimal state estimation result, and completing calibration.
6. The small-angle calibration device of the inertial navigation system is applied to the small-angle calibration method of the inertial navigation system as claimed in any one of claims 1 to 5, and is characterized by comprising the following steps: The accelerometer multi-position calibration module is used for carrying out multi-position calibration on the accelerometer in the inertial navigation system; the gyroscope multi-position calibration module is used for carrying out multi-position calibration on the gyroscope in the inertial navigation system; The small-angle rotation calibration module is used for calibrating the installation error of the gyroscope and the error calibration of the scale factor by using a small-angle speed rotation mode; and the system-level calibration module is used for carrying out system-level calibration on the inertial navigation system.
7. A storage medium comprising at least one instruction which when executed implements the method of any one of claims 1 to 5.

Description

Small-angle calibration method and device for inertial navigation system and storage medium Technical Field The application relates to the technical field of navigation, in particular to a small-angle calibration method and device for an inertial navigation system and a storage medium. Background The laser gyro has the characteristics of high measurement precision and low engineering realization difficulty, and has two to three orders of magnitude higher measurement performance than the existing fiber optic gyro, and along with the engineering of the laser gyro, three laser gyroscopes and accelerometers are required to form laser gyro inertial navigation. The conventional calibration method mainly comprises two types, namely a multi-position calibration method based on earth rotation, has the characteristics of simple calibration method, short calibration period and low calibration precision, and a Gao Jieka Kalman filtering calibration method based on a strapdown inertial navigation error model, namely a system-level calibration method, has the characteristics of accurate modeling, high calibration precision, complex method and long calibration period. The calibration method in the prior art cannot realize high-precision calibration in a shorter period. Disclosure of Invention The application provides a small-angle calibration method of an inertial navigation system, which solves the technical problem that the high-precision calibration cannot be realized in a shorter period in the prior art. In order to achieve the above purpose, the technical scheme adopted by the embodiment of the application is as follows: In an embodiment of the first aspect, the present application provides a small-angle calibration method for an inertial navigation system, including: S1, performing multi-position calibration on an accelerometer in an inertial navigation system to obtain a coarse calibration result of the accelerometer; s2, performing multi-position calibration on the gyroscope in the inertial navigation system to obtain a coarse calibration result of the gyroscope; S3, calibrating the installation error and the scale factor error of the gyroscope by using a small angular velocity rotation mode, and improving the calibration precision of the gyroscope; S4, performing system-level calibration on the inertial navigation system to obtain a high-precision calibration result. According to the application, the accelerometer and the gyroscope are calibrated by adopting a multi-position calibration method, a calibration result with lower precision can be obtained in a shorter period, then the installation error calibration and the scale factor error calibration are performed by adopting a small angular velocity rotation mode, the calibration precision of the gyroscope is further improved, the requirement of automatic calibration of rotation to be counted is met, and finally the inertial navigation system is calibrated at a system level to obtain a high-precision calibration result, so that the technical problem that the calibration method in the prior art cannot realize the high-precision calibration in the shorter period is solved. In some embodiments, the process of multi-position calibration of the accelerometer comprises: S11, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of the turntable, rotating the middle frame shaft, taking a plurality of first angles in the rotating process, and collecting the output of the accelerometer and the output of the turntable at each first angle; s12, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of the turntable, rotating the outer frame shaft to a first preset angle, rotating the middle frame shaft, taking a plurality of first angles in the rotating process, and collecting the output of the accelerometer and the output of the turntable at each first angle; S13, substituting the output of the accelerometer and the output of the turntable into an accelerometer installation error model, and calculating calibration parameters of the accelerometer to obtain zero offset, scale factors and installation errors of the accelerometer. In certain embodiments, the expression of the accelerometer mounting error model is as follows: Wherein KA x、KAy、KAz is the calibration parameter of the accelerometer, and XA i is [1 Sin β -cos βsin γ gcos βcos γ g T, β and γ being the angles of the middle and inner frame axes respectively, a ix、Aiy、Aiz being the output of the accelerometer. In some embodiments, the process of multi-position calibration of the gyroscope includes: S21, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of the turntable, rotating the middle frame shaft, taking a plurality of second angles in the rotating process, and collecting the output of the gyroscope and the output of the turntable at each second angle; S22, zeroing an outer frame shaft, a middle frame shaft and an inner frame shaft of the turntab