CN104121926A - Calibration method for installation error angles between dual-shaft rotation inertial navigation system's rotating shafts and sensitive shafts - Google Patents

Abstract

Belonging to inertial navigation calibration methods, the invention in particular relates to a calibration method for installation error angles between a dual-shaft rotation inertial navigation system's rotating shafts and sensitive shafts. According to the method, four installation error angles delta theta M1, delta gamma M1, delta psi M2, and delta gamma M2 are calibrated, and then compensation is conducted to complete demodulation work of dual-shaft rotation inertial navigation. The specific steps include: 1. calibration and compensation of the inner ring error angles delta theta M1 and delta gamma M1; and 2. calibration and compensation of the inner ring error angles delta psi M2 and delta gamma M2. With the invention, by calibration of the installation error angles between the dual-shaft rotation inertial navigation system's rotating shafts and sensitive shafts, navigation attitude demodulation error caused by the installation error angles can be eliminated, and the navigation attitude precision of the system is improved.

Description

The Calibration Method at alignment error angle between the rotating shaft of twin shaft Rotating Inertial Navigation System and sensitive axes

Technical field

The invention belongs to inertial navigation Calibration Method, be specifically related to the Calibration Method at alignment error angle between the rotating shaft of a kind of twin shaft Rotating Inertial Navigation System and sensitive axes.

Background technology

Rotation modulation technology is a kind of inertial navigation system inertial device error automatic compensatory technique, can be on the basis of existing inertia device level obvious raising system navigation accuracy.Rotating Inertial Navigation System often utilizes rotating mechanism to drive optics strap down inertial navigation assembly (IMU) to carry out continuous rotation or transposition, inertia device with turning axle vertical direction zero offset system is fallen, and utilize code-disc on rotating mechanism to measure the anglec of rotation, the boat appearance of IMU body coordinate system is carried out to demodulation in real time, thereby obtain the boat appearance in the carrier coordinate system after demodulation.Navigation application demand while navigating in order to meet the high precision length such as submarine, can adopt twin shaft Rotating Inertial Navigation System, this system adopts inner and outer ring bi-axial swivel mechanism, according to certain transposition mode, the IMU being arranged in rotating mechanism is rotated to modulation, can modulate all inertia devices zero partially, improve inertial navigation precision.

For twin shaft rotation inertial navigation, IMU is arranged in rotating mechanism, one of them gyro sensitive axes is consistent with inner axle, another gyro sensitive axes is consistent with outer annulate shaft, inside and outside annulate shaft all has code-disc to measure in real time the anglec of rotation separately, navigational computer utilizes this angle to carry out in real time inner and outer ring demodulation to the boat appearance of IMU system, thereby obtains the boat appearance angle in twin shaft inertial navigation system carrier system.

For twin shaft rotary system Practical Project product, due to inside and outside annulate shaft processing and installation accuracy, two turning axle possibility out of plumb; Secondly, IMU is arranged in rotating mechanism and can not strict guarantee gyro sensitive axes overlaps with rotating shaft; In addition, code-disc exists fixed zero error angle also will cause that gyro sensitive axes does not overlap with rotating shaft, and for example the inner axle code-disc error of zero does not overlap the interior gyro sensitive axes of encircling in the surfaces of revolution after causing interior ring demodulation with outer shroud rotating shaft.Because gyro sensitive axes does not overlap with rotating shaft, to separate timing and will bring demodulating error, this error is along with rotating mechanism rotation and fluctuate, and undulating quantity can reach more than angle divides, the system that the has a strong impact on appearance precision of navigating.

Summary of the invention

The Calibration Method that the object of this invention is to provide alignment error angle between the rotating shaft of a kind of twin shaft Rotating Inertial Navigation System and sensitive axes, it carries out calibration by the alignment error angle between the rotating shaft of twin shaft Rotating Inertial Navigation System and sensitive axes, thereby eliminates the boat appearance demodulating error being caused by this alignment error angle.

The present invention is achieved in that the Calibration Method at alignment error angle between the rotating shaft of twin shaft Rotating Inertial Navigation System and sensitive axes, and calibration goes out Δ θ _m1, Δ γ _m1, Δ ψ _m2with Δ γ _m2four alignment error angles, then compensate, and complete the demodulation work of twin shaft rotation inertial navigation, and concrete steps are as follows:

Step 1: interior ring error angle Δ θ _m1, Δ γ _m1calibration and compensation;

Step 2: interior ring error angle Δ ψ _m2, Δ γ _m2calibration and compensation.

Described step 1 comprises the steps,

The first step: system completes after aligning, controls rotating mechanism and makes inner and outer ring get back to code-disc zero-bit, records the boat appearance angle in IMU navigation results, and forms attitude battle array

Second step: control rotating mechanism and make interior ring rotate 180 degree, record the boat appearance angle in IMU navigation results, and form boat appearance battle array

The 3rd step: error of calculation angle Δ θ _m1, Δ γ _m1:

By form matrix $\mathrm{\δC}=C_n^{s\left(180\right)}{C}_s^{n\left(0\right)},$ Have

$\left\{\begin{array}{c}{\mathrm{\Δ\θ}}_{M1}=\frac{\mathrm{\δC}\left(\mathrm{1,2}\right)+\mathrm{\δC}\left(\mathrm{2,1}\right)}{4}\\ {\mathrm{\Δ\γ}}_{M1}=\frac{\mathrm{\δC}\left(\mathrm{3,2}\right)+\mathrm{\δC}\left(\mathrm{2,3}\right)}{4}\end{array}\right.---\left(1\right)$

δ C (i, j) (i, j=1,2,3) wherein

The 4th step: IMU boat appearance is carried out to interior ring demodulation compensation, obtain the boat appearance matrix in B1 system ?

$C_n^{B1}=\left[\begin{array}{ccc}\cos \mathrm{\α}& 0& \sin \mathrm{\α}\\ 0& 1& 0\\ -\sin \mathrm{\α}& 0& \cos \mathrm{\α}\end{array}\right]\left[\begin{array}{ccc}1& -\mathrm{\Δ}{\mathrm{\θ}}_{M1}& 0\\ \mathrm{\Δ}{\mathrm{\θ}}_{M1}& 1& -\mathrm{\Δ}{\mathrm{\γ}}_{M1}\\ 0& \mathrm{\Δ}{\mathrm{\γ}}_{M1}& 1\end{array}\right]C_n^s---\left(2\right)$

Wherein for IMU boat appearance angle.

Described step 2 comprises the steps,

The first step: system completes after aligning, controls rotating mechanism and makes inner and outer ring get back to code-disc zero-bit, records the boat appearance angle in IMU navigation results, and forms attitude battle array by formula (2), obtain

Second step: control rotating mechanism and make outer shroud rotate 180 degree, record the boat appearance angle in IMU navigation results, and form boat appearance battle array

The 3rd step: error of calculation angle Δ ψ _m2, Δ γ _m2:

By form matrix $\mathrm{\δC}=C_n^{B1\left(180\right)}{C}_s^{B1\left(0\right)},$ Have

$\left\{\begin{array}{c}\text{\Δ}{\mathrm{\ψ}}_{M2}=-\frac{\mathrm{\δC}\left(\mathrm{1,3}\right)+\mathrm{\δC}\left(\mathrm{3,1}\right)}{4}\\ \mathrm{\Δ}{\mathrm{\γ}}_{M2}=\frac{\mathrm{\δC}\left(\mathrm{2,3}\right)+\mathrm{\δC}\left(\mathrm{3,2}\right)}{4}\end{array}\right.---\left(3\right)$

δ C (i, j) (i, j=1,2,3) wherein

The 4th step: IMU boat appearance is carried out to outer shroud demodulation compensation, obtain the boat appearance matrix in B2 system ?

$C_n^{B2}=\left[\begin{array}{ccc}\cos \mathrm{\β}& -\sin \mathrm{\β}& 0\\ \sin \mathrm{\β}& \cos \mathrm{\β}& 0\\ 0& 0& 1\end{array}\right]\left[\begin{array}{ccc}1& 0& \mathrm{\Δ}{\mathrm{\ψ}}_{M2}\\ 0& 1& -\mathrm{\Δ}{\mathrm{\γ}}_{M2}\\ -\mathrm{\Δ}{\mathrm{\ψ}}_{M2}& \mathrm{\Δ}{\text{\γ}}_{M2}& 1\end{array}\right]C_n^{B1}---\left(4\right)$

Wherein for the boat appearance matrix in B1 system.

Advantage of the present invention is by the alignment error angle to between the rotating shaft of twin shaft Rotating Inertial Navigation System and sensitive axes, to carry out calibration, thereby eliminate the boat appearance demodulating error being caused by this alignment error angle, the boat appearance precision of raising system.

Embodiment

Below in conjunction with specific embodiment, the present invention is described in detail:

The present invention proposes the Calibration Method at alignment error angle between the rotating shaft of a kind of twin shaft Rotating Inertial Navigation System and sensitive axes, by this Calibration Method, can calibration go out inside and outside two the alignment error angles between inside and outside two rotating shafts of twin shaft rotation inertial navigation and sensitive axes, thereby after calibration completes, eliminating the boat appearance demodulating error being caused by this alignment error angle, improving the boat appearance precision of system.

Twin shaft Rotating Inertial Navigation System inner and outer ring is provided with two kinds, and a kind of is that inner axle is course axle, and another kind is that outer annulate shaft is course axle.For convenience of the elaboration of method, suppose a kind of here: suppose that inner axle is course axle, and during inner and outer ring code-disc zero-bit, wherein two gyro sensitive axes directions of IMU and inner and outer ring rotating shaft are to basically identical.When outer annulate shaft is course axle, method similarly, will be explained in the back.

The coordinate system of first needs being used before carrying out calibration and compensation provides definition and mutual relationship thereof:

A) IMU body coordinate system S: this coordinate is the calibration compensation coordinate system of IMU, connects firmly with IMU, is expressed as OsXsYsZs, while supposing inner and outer ring code-disc zero-bit, Ys is roughly consistent with inner axle direction, and Zs is roughly consistent with outer shroud direction of principal axis;

B) ring code-disc coordinate system M1 in: connect firmly with interior ring code-disc turning axle, rotate with IMU, YM1 direction is interior ring code-disc turning axle direction, suppose that the conversion that S is tied to M1 system only exists horizontal alignment error, and defining angle of pitch error is Δ θ _m1, roll angle error is Δ γ _m1;

C) ring code-disc zero-bit coordinate system B1 in: the M1 while encircling code-disc zero-bit in definition is interior ring code-disc zero-bit coordinate system B1, and coordinate system B1 and inner ring frame frame connect firmly, and M1 is tied to B1 system and only has a course conversion, and encircling code-disc corner in definition is α;

D) outer shroud code-disc coordinate system M2: connect firmly with outer shroud code-disc turning axle, rotate with inner ring frame, ZM2 direction is outer shroud code-disc turning axle direction, supposes that the conversion that B1 is tied to M2 system only exists course and rolling alignment error, and definition course angle alignment error is Δ ψ _m2, roll angle error is Δ γ _m2;

E) outer shroud code-disc zero-bit coordinate system B2: M2 during definition outer shroud code-disc zero-bit is outer shroud code-disc zero-bit coordinate system B2, and coordinate system B2 and outer shroud framework connect firmly, M2 is tied to B2 system and only has an angle of pitch conversion, and definition outer shroud code-disc corner is β;

F) geographic coordinate system n: i.e. north day eastern geographic coordinate system.

This method object is that calibration goes out Δ θ _m1, Δ γ _m1, Δ ψ _m2with Δ γ _m2four alignment error angles, then compensate, and complete the demodulation work of twin shaft rotation inertial navigation.Concrete steps are as follows:

Step 1: interior ring error angle Δ θ _m1, Δ γ _m1calibration and compensation

The first step: system completes after aligning, controls rotating mechanism and makes inner and outer ring get back to code-disc zero-bit, records the boat appearance angle in IMU navigation results, and forms attitude battle array

Second step: control rotating mechanism and make interior ring rotate 180 degree, record the boat appearance angle in IMU navigation results, and form boat appearance battle array

The 3rd step: error of calculation angle Δ θ _m1, Δ γ _m1:

By form matrix $\mathrm{\δC}=C_n^{s\left(180\right)}{C}_s^{n\left(0\right)},$ Have

$\left\{\begin{array}{c}\mathrm{\Δ}{\mathrm{\θ}}_{M1}=\frac{\mathrm{\δC}\left(\mathrm{1,2}\right)+\mathrm{\δC}\left(\mathrm{2,1}\right)}{4}\\ \mathrm{\Δ}{\mathrm{\γ}}_{M1}=-\frac{\mathrm{\δC}\left(\mathrm{3,2}\right)+\mathrm{\δC}\left(\mathrm{2,3}\right)}{4}\end{array}\right.---\left(1\right)$

δ C (i, j) (i, j=1,2,3) wherein.

The 4th step: IMU boat appearance is carried out to interior ring demodulation compensation, obtain the boat appearance matrix in B1 system ?

$C_n^{B1}=\left[\begin{array}{ccc}\cos \mathrm{\α}& 0& \sin \mathrm{\α}\\ 0& 1& 0\\ -\sin \mathrm{\α}& 0& \cos \mathrm{\α}\end{array}\right]\left[\begin{array}{ccc}1& -\mathrm{\Δ}{\mathrm{\θ}}_{M1}& 0\\ \mathrm{\Δ}{\mathrm{\θ}}_{M1}& 1& -\mathrm{\Δ}{\mathrm{\γ}}_{M1}\\ 0& \mathrm{\Δ}{\mathrm{\γ}}_{M1}& 1\end{array}\right]C_n^s---\left(2\right)$

Wherein for IMU boat appearance angle.

Step 2: interior ring error angle Δ ψ _m2, Δ γ _m2calibration and compensation

The first step: system completes after aligning, controls rotating mechanism and makes inner and outer ring get back to code-disc zero-bit, records the boat appearance angle in IMU navigation results, and forms attitude battle array by formula (2), obtain

Second step: control rotating mechanism and make outer shroud rotate 180 degree, record the boat appearance angle in IMU navigation results, and form boat appearance battle array

The 3rd step: error of calculation angle Δ ψ _m2, Δ γ _m2:

By form matrix $\mathrm{\δC}=C_n^{B1\left(180\right)}{C}_s^{B1\left(0\right)},$ Have

$\left\{\begin{array}{c}\text{\Δ}{\mathrm{\ψ}}_{M2}=-\frac{\mathrm{\δC}\left(\mathrm{1,3}\right)+\mathrm{\δC}\left(\mathrm{3,1}\right)}{4}\\ \mathrm{\Δ}{\mathrm{\γ}}_{M2}=\frac{\mathrm{\δC}\left(\mathrm{2,3}\right)+\mathrm{\δC}\left(\mathrm{3,2}\right)}{4}\end{array}\right.---\left(3\right)$

δ C (i, j) (i, j=1,2,3) wherein

The 4th step: IMU boat appearance is carried out to outer shroud demodulation compensation, obtain the boat appearance matrix in B2 system ?

$C_n^{B2}=\left[\begin{array}{ccc}\cos \mathrm{\β}& -\sin \mathrm{\β}& 0\\ \sin \mathrm{\β}& \cos \mathrm{\β}& 0\\ 0& 0& 1\end{array}\right]\left[\begin{array}{ccc}1& 0& \mathrm{\Δ}{\mathrm{\ψ}}_{M2}\\ 0& 1& -\mathrm{\Δ}{\mathrm{\γ}}_{M2}\\ -\mathrm{\Δ}{\mathrm{\ψ}}_{M2}& \mathrm{\Δ}{\text{\γ}}_{M2}& 1\end{array}\right]C_n^{B1}---\left(4\right)$

Wherein for the boat appearance matrix in B1 system.

By above-mentioned steps one and step 2, can calibration go out alignment error angle between the rotating shaft of twin shaft Rotating Inertial Navigation System and sensitive axes, by formula (2) and formula (4), complete whole boat appearance demodulating process.

Need explanation, if outer annulate shaft is course axle, whole step is constant, only needs computing formula (1) and formula (3) to exchange, and formula (2) and formula (4) exchange.

Claims (3)

1. the Calibration Method at alignment error angle between the rotating shaft of twin shaft Rotating Inertial Navigation System and sensitive axes, is characterized in that: calibration goes out Δ θ _m1, Δ γ _m1, Δ ψ _m2with Δ γ _m2four alignment error angles, then compensate, and complete the demodulation work of twin shaft rotation inertial navigation, and concrete steps are as follows:

Step 1: interior ring error angle Δ θ _m1, Δ γ _m1calibration and compensation;

Step 2: interior ring error angle Δ ψ _m2, Δ γ _m2calibration and compensation.

2. the Calibration Method at alignment error angle between twin shaft Rotating Inertial Navigation System as claimed in claim 1 rotating shaft and sensitive axes, is characterized in that: described step 1 comprises the steps,

The first step: system completes after aligning, controls rotating mechanism and makes inner and outer ring get back to code-disc zero-bit, records the boat appearance angle in IMU navigation results, and forms attitude battle array

Second step: control rotating mechanism and make interior ring rotate 180 degree, record the boat appearance angle in IMU navigation results, and form boat appearance battle array

The 3rd step: error of calculation angle Δ θ _m1, Δ γ _m1:

By form matrix $\mathrm{\δC}=C_n^{s\left(180\right)}{C}_s^{n\left(0\right)},$ Have

$\left\{\begin{array}{c}{\mathrm{\Δ\θ}}_{M1}=\frac{\mathrm{\δC}\left(\mathrm{1,2}\right)+\mathrm{\δC}\left(\mathrm{2,1}\right)}{4}\\ {\mathrm{\Δ\γ}}_{M1}=\frac{\mathrm{\δC}\left(\mathrm{3,2}\right)+\mathrm{\δC}\left(\mathrm{2,3}\right)}{4}\end{array}\right.---\left(1\right)$

δ C (i, j) (i, j=1,2,3) wherein

The 4th step: IMU boat appearance is carried out to interior ring demodulation compensation, obtain the boat appearance matrix in B1 system ?

$C_n^{B1}=\left[\begin{array}{ccc}\cos \mathrm{\α}& 0& \sin \mathrm{\α}\\ 0& 1& 0\\ -\sin \mathrm{\α}& 0& \cos \mathrm{\α}\end{array}\right]\left[\begin{array}{ccc}1& -\mathrm{\Δ}{\mathrm{\θ}}_{M1}& 0\\ \mathrm{\Δ}{\mathrm{\θ}}_{M1}& 1& -\mathrm{\Δ}{\mathrm{\γ}}_{M1}\\ 0& \mathrm{\Δ}{\mathrm{\γ}}_{M1}& 1\end{array}\right]C_n^s---\left(2\right)$

Wherein for IMU boat appearance angle.

3. the Calibration Method at alignment error angle between twin shaft Rotating Inertial Navigation System as claimed in claim 1 rotating shaft and sensitive axes, is characterized in that: described step 2 comprises the steps,

The first step: system completes after aligning, controls rotating mechanism and makes inner and outer ring get back to code-disc zero-bit, records the boat appearance angle in IMU navigation results, and forms attitude battle array by formula (2), obtain

Second step: control rotating mechanism and make outer shroud rotate 180 degree, record the boat appearance angle in IMU navigation results, and form boat appearance battle array

The 3rd step: error of calculation angle Δ ψ _m2, Δ γ _m2:

By form matrix $\mathrm{\δC}=C_n^{B1\left(180\right)}{C}_s^{B1\left(0\right)},$ Have

$\left\{\begin{array}{c}\text{\Δ}{\mathrm{\ψ}}_{M2}=-\frac{\mathrm{\δC}\left(\mathrm{1,3}\right)+\mathrm{\δC}\left(\mathrm{3,1}\right)}{4}\\ \mathrm{\Δ}{\mathrm{\γ}}_{M2}=\frac{\mathrm{\δC}\left(\mathrm{2,3}\right)+\mathrm{\δC}\left(\mathrm{3,2}\right)}{4}\end{array}\right.---\left(3\right)$

δ C (i, j) (i, j=1,2,3) wherein

The 4th step: IMU boat appearance is carried out to outer shroud demodulation compensation, obtain the boat appearance matrix in B2 system ?

$C_n^{B2}=\left[\begin{array}{ccc}\cos \mathrm{\β}& -\sin \mathrm{\β}& 0\\ \sin \mathrm{\β}& \cos \mathrm{\β}& 0\\ 0& 0& 1\end{array}\right]\left[\begin{array}{ccc}1& 0& \mathrm{\Δ}{\mathrm{\ψ}}_{M2}\\ 0& 1& -\mathrm{\Δ}{\mathrm{\γ}}_{M2}\\ -\mathrm{\Δ}{\mathrm{\ψ}}_{M2}& \mathrm{\Δ}{\text{\γ}}_{M2}& 1\end{array}\right]C_n^{B1}---\left(4\right)$

Wherein for the boat appearance matrix in B1 system.