CN103940443A - Gyroscope error calibration method - Google Patents

Abstract

The invention belongs to the technical field of inertial navigation, and particularly relates to a gyroscope error calibration method for rapidly calibrating all the error parameter values of a gyroscope by using output values of a system measurement assembly during uniform speed rotation relative to an inertial space. The method comprises that: a strapdown inertial navigation system is arranged on a position change mechanism, the three rotation shafts of the position change mechanism are respectively arranged along the right direction, the front direction and the upper direction of a carrier, aligning is performed after the system is subjected to start-up pre-heating to obtain an initial strapdown attitude matrix, the attitude angle of an IMU coordinate system relative to an inertial coordinate system at the initial time is measured, and the position change mechanism is controlled to drive the IMU to successively rotate according to the measured attitude angles, such that the IMU coordinate system coincides with the inertial coordinate system. According to the present invention, the influence of the high frequency noise in the system can be eliminated, and the IMU rotates relative to the inertial coordinate system so as to make the output signal of the gyroscope be amplified and make the interference resistance strong; and the method has characteristics of simple position change sequence, simple calculation, effective gyroscope calibration speed improvement, and effective gyroscope calibration precision increase.

Description

A kind of method that gyro error is demarcated

Technical field

The invention belongs to inertial navigation technology field, be specifically related to a kind of output valve while utilizing the uniform rotation of systematic survey assembly relative inertness space, Fast Calibration goes out the method that the gyro error of gyrostatic all error parameter value is demarcated.

Background technology

Along with fiber optic gyro strapdown inertial navigation system (Strapdown Inertial Navigation System, SINS) development of technology, people are more and more higher to the performance index accuracy requirement of device, meanwhile in order to reduce the cost of system, need to take efficient system technology, device error is carried out to calibration compensation, thereby improve whole fiber-optic gyroscope strapdown inertial navigation system precision.

Calibration technique is mainly that inertia sensitive element accelerometer to SINS and the fundamental error model parameter of fibre optic gyroscope are determined.Can be divided into element according to the level of demarcating demarcates and system calibrating.Element is demarcated and generally before dispatching from the factory, is carried out in factory by producer, to determine the performance parameter of element.System calibrating refers to from inertial navigation system precision, consider the impact to factors such as the complicated abominables of out of plumb and carrier movement environment of installation shaft while forming inertial navigation system by inertance element, set up the error mathematic model of inertance element, finally realize the process of error compensation.

Conventionally the discrete scaling method adopting is all under geographic coordinate system, provides device error parameter value according to the algebraic operation between the output valve of Inertial Measurement Unit on diverse location (Inertial Measurement Unit, IMU).Although simple in this method principle, because earth autobiography angular velocity information is small at the component of the each axle of geographic coordinate system, and gyrostatic every error is in a small amount, make gyroscope sensitivity to angular velocity information faintly even covered by noise, cause the result of demarcation inaccurate, and transposition is related to that complex calculation amount is larger.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, provide a kind of by controlling IMU relative inertness Space Rotating, gyrostatic output signal integration is provided to Gyroscope error parameter value, and the Fast Calibration that improves the accuracy and runtime of system calibrating goes out the method for gyro error.

The object of the present invention is achieved like this:

Step 1: strapdown inertial navitation system (SINS) is arranged on indexing mechanism, and three rotation axiss of indexing mechanism along the right side-front-upper direction of carrier, are aimed at after system boot preheating respectively, obtain initial strapdown attitude matrix

Step 2: measure the attitude angle of initial time IMU coordinate system relative inertness coordinate system, control indexing mechanism and drive IMU successively to rotate according to the attitude angle of measuring, IMU coordinate system is overlapped with inertial coordinates system;

Step 3: control the z of indexing mechanism around IMU coordinate system _saxle is clockwise taking size as ω _ieangular velocity of rotation rotate T=60s, make the maintenance of IMU coordinate system and Earth central inertial system relative static, measure three normal value gyroscopic drift ε of system _x, ε _yand ε _z:

${\mathrm{\ϵ}}_x=\frac{1}{T}{\∫}_0^T{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}1}^s\mathrm{dt}$

${\mathrm{\ϵ}}_y=\frac{1}{T}{\∫}_0^T{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}1}^s\mathrm{dt}$

${\mathrm{\ϵ}}_z=\frac{1}{T}{\∫}_0^T{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}1}^s\mathrm{dt}$

In formula, be respectively three gyrostatic real-time output valves;

Step 4: control the z of indexing mechanism around IMU coordinate system _saxle is taking size as ω-ω _ieangular velocity rotate counterclockwise 360 degree, wherein ω=20 °/s, measures alignment error A _xy, alignment error A _yxwith scale factor error δ k _gz:

$A_{\mathrm{xy}}=-\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}2}^s\mathrm{dt}+\frac{{\mathrm{\ω\ϵ}}_x}{2\mathrm{\π}}$

$A_{\mathrm{yx}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}2}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_y}{2\mathrm{\π}}$

${\mathrm{\δk}}_{\mathrm{gz}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}2}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_z}{2\mathrm{\π}}$

In formula, be respectively three gyrostatic real-time output valves; T _z=2 π/ω;

Step 5: control the x of IMU around inertial coordinates system _iaxle rotates rapidly 90 degree counterclockwise;

Step 6: control the z of indexing mechanism around IMU coordinate system _saxle is taking size as ω-ω _ieangular velocity rotate counterclockwise 360 degree, measure alignment error A _xz, alignment error A _zxwith scale factor error δ k _gy:

$A_{\mathrm{xz}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}3}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_x}{2\mathrm{\π}}$

${\mathrm{\δk}}_{\mathrm{gy}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}3}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_y}{2\mathrm{\π}}$

$A_{\mathrm{zx}}=-\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}3}^s\mathrm{dt}+\frac{{\mathrm{\ω\ϵ}}_z}{2\mathrm{\π}}$

In formula, be respectively three gyrostatic real-time output valves;

Step 7: control the y of IMU around inertial coordinates system _iaxle rotates rapidly 90 degree clockwise;

Step 8: control the z of indexing mechanism around IMU coordinate system _saxle is taking size as ω-ω _ieangular velocity rotate counterclockwise 360 degree, measure alignment error A _xz, alignment error A _zxwith scale factor error δ k _gy:

${\mathrm{\δk}}_{\mathrm{gz}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}4}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_x}{2\mathrm{\π}}$

$A_{\mathrm{yz}}=-\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}4}^s\mathrm{dt}+\frac{{\mathrm{\ω\ϵ}}_y}{2\mathrm{\π}}$

$A_{\mathrm{zy}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}4}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_z}{2\mathrm{\π}}$

In formula, be respectively three gyrostatic real-time output valves.

Beneficial effect of the present invention is: the present invention has designed a kind of Fast Calibration and go out the method for gyro error, the method can be eliminated the impact of system high-frequency noises, and IMU relative inertness coordinate system rotates and makes gyrostatic output signal increase anti-interference stronger, in addition the method transposition order simple operation is easy, can effectively improve speed and precision that gyroscope is demarcated.

Brief description of the drawings

Fig. 1 is calibration algorithm process flow diagram.

Fig. 2 is the transposition conceptual scheme of demarcating.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described further:

Principle of the present invention is: a kind of method that Fast Calibration goes out gyro error is on the basis of multiposition rotation, overlap with inertial coordinates system by controlling IMU coordinate system, make that three axles of IMU coordinate system are regular to rotate around inertial coordinates system, gyrostatic output valve cycle integrated is got to average and eliminate the impact of system noise on calibration result, then utilize algebraic operation Fast Calibration between the output valve of gyroscope in the time that each axle rotates to go out the error parameter of device.

(1) strapdown inertial navitation system (SINS) is arranged on indexing mechanism, three rotation axiss of indexing mechanism along the right side-front-upper direction of carrier, are aimed at after system boot preheating respectively, obtain initial strapdown attitude matrix

(2) attitude angle of measurement initial time IMU coordinate system relative inertness coordinate system, controls indexing mechanism and drives IMU successively to rotate according to the attitude angle of measuring, and IMU coordinate system is overlapped with inertial coordinates system;

(3) control the z of indexing mechanism around IMU coordinate system _saxle is clockwise taking size as ω _ieangular velocity of rotation rotate, make the maintenance of IMU coordinate system and Earth central inertial system relative static, the now angular velocity of rotation of IMU coordinate system relative inertness coordinate system three gyrostatic output valves with be respectively:

$\left[\begin{array}{c}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}1}^s\\ {\widetilde{\mathrm{\ω}}}_{\mathrm{isy}1}^s\\ {\widetilde{\mathrm{\ω}}}_{\mathrm{isz}1}^s\end{array}\right]=\left[\begin{array}{ccc}1+{\mathrm{\δk}}_{\mathrm{gx}}& A_{\mathrm{xz}}& -A_{\mathrm{xy}}\\ -A_{\mathrm{yz}}& 1+{\mathrm{\δk}}_{\mathrm{gy}}& A_{\mathrm{yx}}\\ A_{\mathrm{zy}}& {-A}_{\mathrm{zx}}& 1+{\mathrm{\δk}}_{\mathrm{gz}}\end{array}\right]{\widehat{\mathrm{\ω}}}_{\mathrm{is}}^s+\left[\begin{array}{c}{\mathrm{\ϵ}}_x\\ {\mathrm{\ϵ}}_y\\ {\mathrm{\ϵ}}_z\end{array}\right]---\left(1\right)$

In formula, δ k _gi, A _ijand ε _i(i, j=x, y, z) represents respectively gyro scale factor error, alignment error and constant error.

Will bring in formula (1) and obtain:

$\left[\begin{array}{c}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}1}^s\\ {\widetilde{\mathrm{\ω}}}_{\mathrm{isy}1}^s\\ {\widetilde{\mathrm{\ω}}}_{\mathrm{isz}1}^s\end{array}\right]=\left[\begin{array}{c}{\mathrm{\ϵ}}_x\\ {\mathrm{\ϵ}}_y\\ {\mathrm{\ϵ}}_z\end{array}\right]---\left(2\right)$

For the impact of Removing Random No, right with cycle integrated is got average, obtains three normal value gyroscopic drift ε _x, ε _yand ε _z:

${\mathrm{\ϵ}}_x=\frac{1}{T}{\∫}_0^T{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}1}^s\mathrm{dt}$

${\mathrm{\ϵ}}_y=\frac{1}{T}{\∫}_0^T{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}1}^s\mathrm{dt}---\left(3\right)$

${\mathrm{\ϵ}}_z=\frac{1}{T}{\∫}_0^T{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}1}^s\mathrm{dt}$

(4) control the z of indexing mechanism around IMU coordinate system _saxle is taking size as (ω-ω _ie) angular velocity rotate counterclockwise 360 degree, wherein ω=20 °/s, now angular velocity of rotation of IMU coordinate system relative inertness coordinate system ${\widehat{\mathrm{\ω}}}_{\mathrm{is}}^s{\left[\begin{array}{ccc}0& 0& \mathrm{\ω}\end{array}\right]}^T,$ Measure A according to formula (4) _xy, A _yxwith δ k _gz:

$A_{\mathrm{xy}}=-\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}2}^s\mathrm{dt}+\frac{{\mathrm{\ω\ϵ}}_x}{2\mathrm{\π}}$

$A_{\mathrm{yx}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}2}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_y}{2\mathrm{\π}}---\left(4\right)$

${\mathrm{\δk}}_{\mathrm{gz}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}2}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_z}{2\mathrm{\π}}$

In formula, be respectively three gyrostatic real-time output valves; T _z=2 π/ω.

(5) control the x of IMU around inertial coordinates system _iaxle rotates rapidly 90 degree counterclockwise;

(6) control the z of indexing mechanism around IMU coordinate system _saxle is taking size as (ω-ω _ie) angular velocity rotate counterclockwise 360 degree, the now angular velocity of rotation of IMU coordinate system relative inertness coordinate system ${\widehat{\mathrm{\ω}}}_{\mathrm{is}}^s{\left[\begin{array}{ccc}0& \mathrm{\ω}& 0\end{array}\right]}^T,$ Measure A according to formula (5) _xz, A _zxwith δ k _gy:

$A_{\mathrm{xz}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_x}{2\mathrm{\π}}$

${\mathrm{\δk}}_{\mathrm{gy}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_y}{2\mathrm{\π}}---\left(5\right)$

$A_{\mathrm{zx}}=-\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}}^s\mathrm{dt}+\frac{{\mathrm{\ω\ϵ}}_z}{2\mathrm{\π}}$

(7) control the y of IMU around inertial coordinates system _iaxle rotates rapidly 90 degree clockwise;

(8) control the z of indexing mechanism around IMU coordinate system _saxle is taking size as (ω-ω _ie) angular velocity rotate counterclockwise 360 degree, the now angular velocity of rotation of IMU coordinate system relative inertness coordinate system ${\widehat{\mathrm{\ω}}}_{\mathrm{is}}^s{\left[\begin{array}{ccc}\mathrm{\ω}& 0& 0\end{array}\right]}^T$ Measure A according to formula (6) _xz, A _zxwith δ k _gy:

${\mathrm{\δk}}_{\mathrm{gz}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_x}{2\mathrm{\π}}$

$A_{\mathrm{yz}}=-\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}}^s\mathrm{dt}+\frac{{\mathrm{\ω\ϵ}}_y}{2\mathrm{\π}}---\left(6\right)$

$A_{\mathrm{zy}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_z}{2\mathrm{\π}}$ 。

Claims (1)

1. the method that gyro error is demarcated, is characterized in that, comprises the following steps:

Step 1: strapdown inertial navitation system (SINS) is arranged on indexing mechanism, and three rotation axiss of indexing mechanism along the right side-front-upper direction of carrier, are aimed at after system boot preheating respectively, obtain initial strapdown attitude matrix

Step 2: measure the attitude angle of initial time IMU coordinate system relative inertness coordinate system, control indexing mechanism and drive IMU successively to rotate according to the attitude angle of measuring, IMU coordinate system is overlapped with inertial coordinates system;

Step 3: control the z of indexing mechanism around IMU coordinate system _saxle is clockwise taking size as ω _ieangular velocity of rotation rotate T=60s, make the maintenance of IMU coordinate system and Earth central inertial system relative static, measure three normal value gyroscopic drift ε of system _x, ε _yand ε _z:

${\mathrm{\ϵ}}_x=\frac{1}{T}{\∫}_0^T{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}1}^s\mathrm{dt}$

${\mathrm{\ϵ}}_y=\frac{1}{T}{\∫}_0^T{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}1}^s\mathrm{dt}$

${\mathrm{\ϵ}}_z=\frac{1}{T}{\∫}_0^T{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}1}^s\mathrm{dt}$

In formula, be respectively three gyrostatic real-time output valves;

Step 4: control the z of indexing mechanism around IMU coordinate system _saxle is taking size as ω-ω _ieangular velocity rotate counterclockwise 360 degree, wherein ω=20 °/s, measures alignment error A _xy, alignment error A _yxwith scale factor error δ k _gz:

$A_{\mathrm{xy}}=-\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}2}^s\mathrm{dt}+\frac{{\mathrm{\ω\ϵ}}_x}{2\mathrm{\π}}$

$A_{\mathrm{yx}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}2}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_y}{2\mathrm{\π}}$

${\mathrm{\δk}}_{\mathrm{gz}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}2}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_z}{2\mathrm{\π}}$

In formula, be respectively three gyrostatic real-time output valves; T _z=2 π/ω;

Step 5: control the x of IMU around inertial coordinates system _iaxle rotates rapidly 90 degree counterclockwise;

Step 6: control the z of indexing mechanism around IMU coordinate system _saxle is taking size as ω-ω _ieangular velocity rotate counterclockwise 360 degree, measure alignment error A _xz, alignment error A _zxwith scale factor error δ k _gy:

$A_{\mathrm{xz}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}3}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_x}{2\mathrm{\π}}$

${\mathrm{\δk}}_{\mathrm{gy}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}3}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_y}{2\mathrm{\π}}$

$A_{\mathrm{zx}}=-\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}3}^s\mathrm{dt}+\frac{{\mathrm{\ω\ϵ}}_z}{2\mathrm{\π}}$

In formula, be respectively three gyrostatic real-time output valves;

Step 7: control the y of IMU around inertial coordinates system _iaxle rotates rapidly 90 degree clockwise;

Step 8: control the z of indexing mechanism around IMU coordinate system _saxle is taking size as ω-ω _ieangular velocity rotate counterclockwise 360 degree, measure alignment error A _xz, alignment error A _zxwith scale factor error δ k _gy:

${\mathrm{\δk}}_{\mathrm{gz}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isx}4}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_x}{2\mathrm{\π}}$

$A_{\mathrm{yz}}=-\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isy}4}^s\mathrm{dt}+\frac{{\mathrm{\ω\ϵ}}_y}{2\mathrm{\π}}$

$A_{\mathrm{zy}}=\frac{1}{2\mathrm{\π}}{\∫}_0^{T_z}{\widetilde{\mathrm{\ω}}}_{\mathrm{isz}4}^s\mathrm{dt}-\frac{{\mathrm{\ω\ϵ}}_z}{2\mathrm{\π}}$

In formula, be respectively three gyrostatic real-time output valves.