CN100588906C - Carrier posture measuring method suitable for optical fiber gyroscope - Google Patents

Abstract

The invention discloses a measuring method for a carrier gesture of an optical fiber gyro, which comprises determining an initial position parameter and an initial speed value of a carrier through anexternal device, initially aligning strapdown inertial navigation system of the optical fiber gyro, determining an initial gesture of the carrier which is relative to a navigation coordinate system, obtaining an initial value of a gesture hypercomplex number, determining a gesture renewal cycle H = tm-tm-1, calculating an increment delta phi of rotating vector through collecting a carrier which isoutput by the optical fiber gyro which is corresponded to an angle speed of the inertial coordinate system, obtaining a gesture renewal hypercomplex number q(H) of the gesture renewal cycle H througha relation of the rotating vector and the hypercomplex number, renewing the gesture hypercomplex number through a renewal equation of the gesture hypercomplex number, calculating a strapdown matrix Tthat a carrier coordinate system b is relative to a navigation coordinate system n, and obtaining a gesture angle of the carrier which is relative to the navigation coordinate system and the like. The invention solves the problem that a cone effect influences a measuring accuracy of the carrier gesture under a high dynamic environment of a carrier or a high-frequency vibration environment.

Description

The carrier posture measuring method that is suitable for optical fibre gyro

(1) technical field

The present invention is to provide a kind of measuring method, specifically a kind of to use optical fibre gyro to measure carrier be the method for attitude parameter with respect to navigation coordinate.

(2) background technology

In strapdown inertial navigation system, inertial sensor (gyro and accelerometer) directly connects firmly on carrier.Their sensitive carriers change and velocity variations information with respect to the attitude of inertial coordinates system, the processing output navigational parameter of these information via navigational computers, thus finish the navigational guidance task.Because the mode that adopts inertial sensor to connect firmly, the vibration of the direct sensitive carrier of inertial sensor meeting and the interference of environment bring certain influence to the measuring accuracy of strapdown inertial navigation system.In strapdown inertial navigation system, employing be mathematical platform, mainly rely on the output information of gyro to make up mathematical platform, to describe the attitude of the relative navigation coordinate of carrier system.And gyro is output as angle increment or angular velocity, can not be directly used in the relativeness of describing coordinate system.In the attitude measurement method of the strapdown inertial navigation system of routine, always think that the conversion between carrier coordinate system and navigation coordinate system realizes by a series of rotation.So,, need try to achieve hypercomplex number or the rotating vector of describing the coordinate system relation by corresponding angular velocity or angle increment in order to measure the attitude of carrier.But under high dynamic environment, be different in the position of each gyro sampling corresponding vectors coordinate system of posture renewal in the cycle.In addition, be that the order of the rotation of hypothesis between from the carrier coordinate system to the reference frame can not considered in the classic method, this is based on infinitely small rotation is that the principle of vector obtains.But in the practical project, particularly under high dynamic mobility situation of carrier or abominable vibration environment, the rotation of carrier usually is limited rotation, and limited rotation is not a vector, and it rotates order and can not exchange.Thereby traditional attitude measurement method of finding the solution hypercomplex number after the angle increment summation with all gyro outputs of posture renewal in the cycle again will bring bigger error, i.e. coning error.Coning error is similar to gyroscopic drift, brings negative effect for the attitude measurement of carrier.The complement taper error, the attitude of measuring carrier in high quality just must the high performance attitude measurement method of design.

In traditional attitude measurement method, utilize the angle increment of gyro output to go to estimate the circular cone compensation term, thereby estimate the increment of rotating vector.These basic ideas are based in the output of traditional gyro, and obtaining of angle increment is very easily.The increment that promptly will expect rotating vector must be known the angle increment of gyro output.And in present widely used fiber optic gyro strapdown inertial navigation system, the output signal of optical fibre gyro is an angular velocity information, and for this reason, common way is to adopt piece-wise linearization, thinks that the angular velocity of carrier is constant in each sampling period.Set up when this hypothesis and angular velocity varies carrier enough little in the sampling period is slower, considered but just must add in addition for the dynamic occasion of height.Available research achievements shows, under the situation of optical fibre gyro output angle speed, for traditional attitude measurement method based on rotating vector, performance can't be embodied in the superiority of reply cone effect not as the conventional attitude measurement method based on hypercomplex number.

(3) summary of the invention

The object of the present invention is to provide a kind of can the solution in carrier high dynamic environment or high-frequency vibration environment, the carrier posture measuring method that is suitable for optical fibre gyro of the problem that cone effect exerts an influence for the attitude of carrier measuring accuracy.

The object of the present invention is achieved like this:

Step 1, determine the initial position parameters and the initial velocity value of carrier by external unit;

Step 2, fiber optic gyro strapdown inertial navigation system carry out initial alignment, determine the initial attitude of the relative navigation coordinate of carrier system, obtain the initial value of attitude quaternion;

Step 3, determine posture renewal cycle H=t _m-t _M-1, described posture renewal cycle H equals N optical fibre gyro sampling period h=t doubly _l-t _L-1, described N is the integer greater than zero;

The carrier of step 4, the output of collection optical fibre gyro is with respect to the increment Delta φ of the angular speed calculation rotating vector of inertial coordinates system;

Step 5, by the relation of rotating vector and hypercomplex number, obtain posture renewal hypercomplex number q (H) in the posture renewal cycle H,

Wherein

Be the mould of rotating vector increment,

Step 6, upgrade attitude quaternion by the attitude quaternion renewal equation

$Q\left(t_m\right)=Q\left(t_{m-1}\right)\⊗q\left(H\right)$

Wherein posture renewal hypercomplex number q (H) is obtained by step 5, Q (t _m), Q (t _M-1) represent that respectively carrier is at t _m, t _M-1Attitude quaternion constantly;

Step 7, the t that utilizes step 6 to obtain _mMoment attitude quaternion Q (t _m)=[q ₀q ₁q ₂q ₃] ^TCalculating carrier coordinate system b system is the strapdown matrix T of n system with respect to navigation coordinate,

$T=\left[\begin{array}{ccc}{T}_{11}& T_{12}& T_{13}\\ T_{21}& T_{22}& T_{23}\\ T_{31}& T_{32}& T_{33}\end{array}\right]=\left[\begin{array}{ccc}{q_0}^2+{q_1}^2-{{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_2}^2-{{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3}^2& 2(q_1{q}_2-q_0{q}_3)& 2(q_1{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3+q_0{q}_2)\\ 2(q_1{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_2+q_0{q}_3)& {q_0}^2-{q_1}^2+{{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_2}^2+{{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3}^2& 2(q_2{q}_3-q_0{q}_1)\\ 2(q_1{q}_3-q_0{q}_2)& 2(q_2{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3+q_0{q}_1)& {q_0}^2-{q_1}^2-{{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_2}^2+{{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3}^2\end{array}\right]$

Step 8, the strapdown matrix T of utilizing step 7 to obtain are tried to achieve the attitude angle of the relative navigation coordinate of carrier system, navigation coordinate system is chosen for the azimuthal coordinates system of moving about, then the grid heading angle ψ of carrier, pitch angle θ, roll angle γ can usually be represented by the unit in the strapdown matrix T

${\mathrm{\&psi;}}_0=\arctan (-\frac{T_{12}}{T_{22}})$

θ ₀＝arcsinT ₃₂

${\mathrm{\&gamma;}}_0=\arctan (-\frac{T_{31}}{T_{33}})$

Wherein the field of definition of grid heading angle ψ is (0 a °, 360 °); The field of definition of pitch angle θ is (90 °, 90 °); The field of definition of roll angle γ is (90 °, 90 °),

Obtain their true value by the field of definition of attitude angle,

The true value at grid heading angle is

The true value of pitch angle is

θ＝θ ₀

The true value of roll angle is

The present invention can also comprise:

1, the initial position at the carrier described in the step 1 is provided by GPS device or outside high-precision integrated navigation equipment, and the initial velocity value of described carrier is provided by DVL Doppler log or outside high-precision integrated navigation equipment.

2, determine to be divided into two kinds of situations at the initial attitude of the relative navigation coordinate of the carrier described in the step 2 system: when carrier is in quiet pedestal, adopt Alignment Method based on classic control theory; When carrier is in moving pedestal, adopt combination alignment methods based on kalman filtering theory.

3, the calculating concrete steps at the rotating vector increment Delta φ described in the step 4 are as follows:

Step 41: can survey item by the inertia that the output of optical fibre gyro output is calculated among the Δ φ, i.e. angle increment α; The H=Nh that concerns by posture renewal cycle and optical fibre gyro sampling period; Known N+1 optical fibre gyro sampling angular velocity omega in each posture renewal cycle H ₀, ω ₁, L ω _NThen the angle increment α in the posture renewal cycle H is

$\mathrm{\&alpha;}=H\underset{k=0}{\overset{N}{\mathrm{\&Sigma;}}}{C}_k^N{\mathrm{\&omega;}}_k$

Wherein

$C_k^N=\frac{{(-1)}^{N-k}}{\mathrm{Nk}!(N-k)!}{\&Integral;}_0^N\underset{j\&NotEqual;k}{\overset{N}{\underset{j=0}{\mathrm{\&Pi;}}}}(t-j)\mathrm{dt},(k=\mathrm{0,1},\mathrm{L\; N});$

Step 42: can survey item by the non-inertia that the output of optical fibre gyro output is calculated among the Δ φ, i.e. circular cone compensation term β; The H=Nh that concerns by posture renewal cycle and optical fibre gyro sampling period; Known N+1 optical fibre gyro sampling angular velocity omega in each posture renewal cycle H ₀, ω ₁, L ω _N

In the posture renewal cycle H, circular cone compensation term β is calculated by the linear combination of optical fibre gyro sampling angular velocity multiplication cross item

$\mathrm{\&beta;}={\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">h</figure-callout>}}^2\underset{i=1}{\overset{N-1}{\mathrm{\&Sigma;}}}{K}_{N-i}({\mathrm{\&omega;}}_i\&times;{\mathrm{\&omega;}}_N)$

K wherein _N-iFor optimizing coefficient, in the typical cone environment, determine;

Step 43:,, obtain rotating vector increment Delta φ in the posture renewal cycle H with the posture renewal cycle H female cone compensation term β addition that obtains in the step 41 with angle increment α in the posture renewal cycle H that obtains in the step 41;

Δφ＝α+β

N=3 is set, and gyro is at the t angular velocity omega of sampling constantly ₀, and each posture renewal cycle H is at t+H/3, t+2H/3, the t+H ω that samples constantly ₁, ω ₂, ω ₃Obtaining the interior rotating vector increment Delta φ of posture renewal cycle H is

$\mathrm{\&Delta;\&phi;}=\mathrm{\&alpha;}+h^2(\frac{87}{2240}{\mathrm{\&omega;}}_0\&times;{\mathrm{\&omega;}}_3+\frac{27}{56}{\mathrm{\&omega;}}_1\&times;{\mathrm{\&omega;}}_3+\frac{2619}{2240}{\mathrm{\&omega;}}_2\&times;{\mathrm{\&omega;}}_3)$

Wherein

$\mathrm{\&alpha;}=\frac{H}{8}({\mathrm{\&omega;}}_0+3{\mathrm{\&omega;}}_1+{3\mathrm{\&omega;}}_2+{\mathrm{\&omega;}}_3),$ H＝3h

N=2 is set, and gyro is at the t angular velocity omega of sampling constantly ₀, and in each computation period H, at t+H/2, the t+H ω that samples constantly twice ₁, ω ₂Obtaining the interior rotating vector increment Delta φ of posture renewal cycle H is

$\mathrm{\&Delta;\&phi;}=\mathrm{\&alpha;}+h^2(\frac{1}{45}{\mathrm{\&omega;}}_0\&times;{\mathrm{\&omega;}}_2+\frac{28}{45}{\mathrm{\&omega;}}_1\&times;{\mathrm{\&omega;}}_2)$

Wherein

$\mathrm{\&alpha;}=\frac{H}{6}({\mathrm{\&omega;}}_0+4{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2),$ H＝2h。

The present invention compare with classic method advantage be mainly reflected in:

(1) be output as the situation of angular velocity at optical fibre gyro, be different from traditional measurement method with angle increment as input, inventive method is directly with the angular velocity input, fits the circular cone compensation term with the multiplication cross item of angular velocity.When having avoided the use optical fibre gyro, classic method is for the measured deviation of sculling compensation item.

(2) with respect to the another kind of approach that improves strapdown inertial navigation system Attitude Calculation precision: select high performance optical fibre gyro for use.The measuring method of invention only need be done the navigation software design, does not need to increase the manufacturing cost of strapdown inertial navigation system.

(4) description of drawings

Fig. 1 is the attitude measurement method process flow diagram of suitable fiber optic gyro strapdown inertial navigation system of the present invention.

Fig. 2 is in the typical cone environment, the attitude measurement method of invention; The empirical curve of traditional attitude measurement method.The typical cone environment is defined as: have same frequency on two orthogonal axes of carrier, the angular oscillation of phase differential 90 degree.The sample frequency of optical fibre gyro is 100Hz.

(5) embodiment

For example the present invention is done description in more detail below in conjunction with accompanying drawing:

In conjunction with Fig. 1, the attitude measurement method that is suitable for fiber optic gyro strapdown inertial navigation system of the present invention comprises the steps:

Step 1, determine the initial position parameters and the initial velocity value of carrier by external unit.

Step 2, fiber optic gyro strapdown inertial navigation system carry out initial alignment, determine the initial attitude of the relative navigation coordinate of carrier system, obtain the initial value of attitude quaternion.

Step 3, determine posture renewal cycle H=t _m-t _M-1, described posture renewal cycle H equals N optical fibre gyro sampling period h=t doubly _l-t _L-1Described N is the integer greater than zero.

The carrier of step 4, the output of collection optical fibre gyro is with respect to the increment Delta φ of the angular speed calculation rotating vector of inertial coordinates system.

Step 5, by the relation of rotating vector and hypercomplex number, obtain posture renewal hypercomplex number q (H) in the posture renewal cycle H.

Wherein

Mould for the rotating vector increment.

Step 6, upgrade attitude quaternion by the attitude quaternion renewal equation

$Q\left(t_m\right)=Q\left(t_{m-1}\right)\&CircleTimes;q\left(H\right)---\left(2\right)$

Wherein posture renewal hypercomplex number q (H) is tried to achieve by step 5.Q (t _m), Q (t _M-1) represent that respectively carrier is at t _m, t _M-1Attitude quaternion constantly.

Step 7, the t that utilizes step 6 to obtain _mMoment attitude quaternion Q (t _m)=[q ₀q ₁q ₂q ₃] ^TCalculating carrier coordinate system b system is the strapdown matrix T of n system with respect to navigation coordinate.

$T=\left[\begin{array}{ccc}{T}_{11}& T_{12}& T_{13}\\ T_{21}& T_{22}& T_{23}\\ T_{31}& T_{32}& T_{33}\end{array}\right]=\left[\begin{array}{ccc}{q_0}^2+{q_1}^2-{{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_2}^2-{{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3}^2& 2(q_1{q}_2-q_0{q}_3)& 2(q_1{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3+q_0{q}_2)\\ 2(q_1{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_2+q_0{q}_3)& {q_0}^2-{q_1}^2+{{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_2}^2+{{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3}^2& 2(q_2{q}_3-q_0{q}_1)\\ 2(q_1{q}_3-q_0{q}_2)& 2(q_2{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3+q_0{q}_1)& {q_0}^2-{q_1}^2-{{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_2}^2+{{\mathrm{<figure-callout\; id="3"\; label="q"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">q</figure-callout>}}_3}^2\end{array}\right]---\left(3\right)$

Step 8, the strapdown matrix T of utilizing step 7 to obtain are tried to achieve the attitude angle of the relative navigation coordinate of carrier system.Navigation coordinate system is chosen for the azimuthal coordinates system of moving about, and then the grid heading angle ψ of carrier, pitch angle θ, roll angle γ can usually be represented by the unit in the strapdown matrix T.

${\mathrm{\&psi;}}_0=\arctan (-\frac{T_{12}}{T_{22}})$

θ ₀＝arcsinT ₃₂(4)

${\mathrm{\&gamma;}}_0=\arctan (-\frac{T_{31}}{T_{33}})$

Wherein the field of definition of grid heading angle ψ is (0 a °, 360 °); The field of definition of pitch angle θ is (90 °, 90 °); The field of definition of roll angle γ is (90 °, 90 °).

Can determine their true value by the field of definition of attitude angle.The true value at grid heading angle is

The true value of pitch angle is

θ＝θ ₀

The true value of roll angle is

Initial position at the carrier described in the step 1 is provided by GPS device or outside high-precision integrated navigation equipment, and the initial velocity value of described carrier is provided by DVL Doppler log or outside high-precision integrated navigation equipment.

Initial attitude in the relative navigation coordinate of the carrier described in the step 2 system determines to be divided into two kinds of situations: when carrier is in quiet pedestal, can adopt the Alignment Method based on classic control theory; When carrier is in moving pedestal, can adopt combination alignment methods based on kalman filtering theory.

Calculating concrete steps at the rotating vector increment Delta φ described in the step 4 are as follows:

Step 41: can survey item by the inertia that the output of optical fibre gyro output is calculated among the Δ φ, i.e. angle increment α.The H=Nh that concerns by posture renewal cycle and optical fibre gyro sampling period.Known N+1 optical fibre gyro sampling angular velocity omega in each posture renewal cycle H ₀, ω ₁, L ω _NThen the angle increment α in the posture renewal cycle H is

$\mathrm{\&alpha;}=H\underset{k=0}{\overset{N}{\mathrm{\&Sigma;}}}{C}_k^N{\mathrm{\&omega;}}_k---\left(5\right)$

Wherein

$C_k^N=\frac{{(-1)}^{N-k}}{\mathrm{Nk}!(N-k)!}{\&Integral;}_0^N\underset{j\&NotEqual;k}{\overset{N}{\underset{j=0}{\mathrm{\&Pi;}}}}(t-j)\mathrm{dt},(k=\mathrm{0,1},\mathrm{L\; N})---\left(6\right)$

Step 42: can survey item by the non-inertia that the output of optical fibre gyro output is calculated among the Δ φ, i.e. circular cone compensation term β.The H=Nh that concerns by posture renewal cycle and optical fibre gyro sampling period.Known N+1 optical fibre gyro sampling angular velocity omega in each posture renewal cycle H ₀, ω ₁, L ω _N

In the posture renewal cycle H, circular cone compensation term β can be calculated by the sample linear combination of angular velocity multiplication cross item of optical fibre gyro

$\mathrm{\&beta;}={\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="C2007101448460015H1.png"\; state="\{\{state\}\}">h</figure-callout>}}^2\underset{i=1}{\overset{N-1}{\mathrm{\&Sigma;}}}{K}_{N-i}({\mathrm{\&omega;}}_i\&times;{\mathrm{\&omega;}}_N)---\left(7\right)$

K wherein _N-iFor optimizing coefficient, can in the typical cone environment, determine.

Step 43:,, obtain rotating vector increment Delta φ in the posture renewal cycle H with the posture renewal cycle H female cone compensation term β addition that obtains in the step 41 with angle increment α in the posture renewal cycle H that obtains in the step 41.

Δφ＝α+β(8)

N=3 is set, and gyro is at the t angular velocity omega of sampling constantly ₀, and each posture renewal cycle H is at t+H/3, t+2H/3, the t+H ω that samples constantly ₁, ω ₂, ω ₃Obtaining the interior rotating vector increment Delta φ of posture renewal cycle H is

$\mathrm{\&Delta;\&phi;}=\mathrm{\&alpha;}+h^2(\frac{87}{2240}{\mathrm{\&omega;}}_0\&times;{\mathrm{\&omega;}}_3+\frac{27}{56}{\mathrm{\&omega;}}_1\&times;{\mathrm{\&omega;}}_3+\frac{2619}{2240}{\mathrm{\&omega;}}_2\&times;{\mathrm{\&omega;}}_3)---\left(9\right)$

Wherein

$\mathrm{\&alpha;}=\frac{H}{8}({\mathrm{\&omega;}}_0+3{\mathrm{\&omega;}}_1+{3\mathrm{\&omega;}}_2+{\mathrm{\&omega;}}_3),$ H＝3h

N=2 is set, and gyro is at the t angular velocity omega of sampling constantly ₀, and in each computation period H, at t+H/2, the t+H ω that samples constantly twice ₁, ω ₂Obtaining the interior rotating vector increment Delta φ of posture renewal cycle H is

$\mathrm{\&Delta;\&phi;}=\mathrm{\&alpha;}+h^2(\frac{1}{45}{\mathrm{\&omega;}}_0\&times;{\mathrm{\&omega;}}_2+\frac{28}{45}{\mathrm{\&omega;}}_1\&times;{\mathrm{\&omega;}}_2)---\left(10\right)$

Wherein

$\mathrm{\&alpha;}=\frac{H}{6}({\mathrm{\&omega;}}_0+4{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2),$ H＝2h

In the posture renewal cycle H, the employed optical fibre gyro hits of attitude measurement method is many more, and the effect of attitude measurement method reply circular cone compensation is just good more, and the attitude accuracy of fiber optic gyro strapdown inertial navigation system output is just high more.

Claims (3)

1, a kind of carrier posture measuring method that is suitable for optical fibre gyro is characterized in that:

Step 1, determine the initial position parameters and the initial velocity value of carrier by external unit;

Step 2, fiber optic gyro strapdown inertial navigation system carry out initial alignment, determine the initial attitude of the relative navigation coordinate of carrier system, obtain the initial value of attitude quaternion;

Step 3, determine posture renewal cycle H=t _m-t _M-1, described posture renewal cycle H equals N optical fibre gyro sampling period h=t doubly _l-t _L-1, described N is the integer greater than zero;

The carrier of step 4, the output of collection optical fibre gyro is with respect to the increment Delta φ of the angular speed calculation rotating vector of inertial coordinates system, and concrete steps are as follows:

Step 41: can survey item by the inertia that the output of optical fibre gyro output is calculated among the Δ φ, i.e. angle increment α; The H=Nh that concerns by posture renewal cycle and optical fibre gyro sampling period; Known N+1 optical fibre gyro sampling angular velocity omega in each posture renewal cycle H ₀, ω ₁... ω _NThen the angle increment α in the posture renewal cycle H is

$\mathrm{\&alpha;}=H\underset{k=0}{\overset{N}{\mathrm{\&Sigma;}}}{C}_k^N{\mathrm{\&omega;}}_k$

Wherein

$C_k^N=\frac{{(-1)}^{N-k}}{\mathrm{Nk}!(N-k)!}{\&Integral;}_0^N\underset{j\&NotEqual;k}{\overset{N}{\underset{j=0}{\mathrm{\&Sigma;}}}}(t-j)\mathrm{dt}(k=\mathrm{0,1},\&CenterDot;\&CenterDot;\&CenterDot;N);$

Step 42: can survey item by the non-inertia that the output of optical fibre gyro output is calculated among the Δ φ, i.e. circular cone compensation term β; The H=Nh that concerns by posture renewal cycle and optical fibre gyro sampling period; Known N+1 optical fibre gyro sampling angular velocity omega in each posture renewal cycle H ₀, ω ₁... ω _N

In the posture renewal cycle H, circular cone compensation term β is calculated by the linear combination of optical fibre gyro sampling angular velocity multiplication cross item

$\mathrm{\&beta;}=h^2\underset{i=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{K}_{N-i}({\mathrm{\&omega;}}_i\&times;{\mathrm{\&omega;}}_N)$

K wherein _N-iFor optimizing coefficient, in the typical cone environment, determine;

Step 43:,, obtain rotating vector increment Delta φ in the posture renewal cycle H with the posture renewal cycle H female cone compensation term β addition that obtains in the step 41 with angle increment α in the posture renewal cycle H that obtains in the step 41;

Δφ＝α+β

N=3 is set, and gyro is at the t angular velocity omega of sampling constantly ₀, and each posture renewal cycle H is at t+H/3, t+2H/3, the t+H ω that samples constantly ₁, ω ₂, ω ₃Obtaining the interior rotating vector increment Delta φ of posture renewal cycle H is

$\mathrm{\&Delta;\&phi;}=\mathrm{\&alpha;}+h^2(\frac{87}{2240}{\mathrm{\&omega;}}_0\&times;{\mathrm{\&omega;}}_3+\frac{27}{56}{\mathrm{\&omega;}}_1\&times;{\mathrm{\&omega;}}_3+\frac{2619}{2240}{\mathrm{\&omega;}}_2\&times;{\mathrm{\&omega;}}_3)$

Wherein

$\mathrm{\&alpha;}=\frac{H}{8}({\mathrm{\&omega;}}_0+3{\mathrm{\&omega;}}_1+3{\mathrm{\&omega;}}_2+{\mathrm{\&omega;}}_3),H=3h$

N=2 is set, and gyro is at the t angular velocity omega of sampling constantly ₀, and in each computation period H, at t+H/2, the t+H ω that samples constantly twice ₁, ω ₂Obtaining the interior rotating vector increment Delta φ of posture renewal cycle H is

$\mathrm{\&Delta;\&phi;}=\mathrm{\&alpha;}+h^2(\frac{1}{45}{\mathrm{\&omega;}}_0\&times;{\mathrm{\&omega;}}_2+\frac{28}{45}{\mathrm{\&omega;}}_1\&times;{\mathrm{\&omega;}}_2)$

Wherein

$\mathrm{\&alpha;}=\frac{H}{6}({\mathrm{\&omega;}}_0+4{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2),H=2h;$

Step 5, by the relation of rotating vector and hypercomplex number, obtain posture renewal hypercomplex number q (H) in the posture renewal cycle H,

Wherein

Be the mould of rotating vector increment,

Step 6, upgrade attitude quaternion by the attitude quaternion renewal equation

$Q\left(t_m\right)=Q\left(t_{m-1}\right)\&CircleTimes;q\left(H\right)$

Wherein posture renewal hypercomplex number q (H) is obtained by step 5, Q (t _m), Q (t _M-1) represent that respectively carrier is at t _m, t _M-1Attitude quaternion constantly;

Step 7, the t that utilizes step 6 to obtain _mMoment attitude quaternion Q (t _m)=[q ₀q ₁q ₂q ₃] ^TCalculating carrier coordinate system b system is the strapdown matrix T of n system with respect to navigation coordinate,

$T=\left[\begin{array}{ccc}{T}_{11}& T_{12}& T_{13}\\ T_{21}& T_{22}& T_{23}\\ T_{31}& T_{32}& T_{33}\end{array}\right]=\left[\begin{array}{ccc}{q_0}^2+{q_1}^2-{q_2}^2-{q_3}^2& 2(q_1{q}_2-q_0{q}_3)& 2(q_1{q}_3+q_0{q}_2)\\ 2(q_1{q}_2+q_0{q}_3)& {q_0}^2-{q_1}^2+{q_2}^2+{q_3}^2& 2(q_2{q}_3-q_0{q}_1)\\ 2(q_1{q}_3-q_0{q}_2)& 2(q_2{q}_3+q_0{q}_1)& {q_0}^2-{q_1}^2-{q_2}^2+{q_3}^2\end{array}\right]$

Step 8, the strapdown matrix T of utilizing step 7 to obtain are tried to achieve the attitude angle of the relative navigation coordinate of carrier system, navigation coordinate system is chosen for the azimuthal coordinates system of moving about, then the grid heading angle ψ of carrier, pitch angle θ, roll angle γ can usually be represented by the unit in the strapdown matrix T

${\mathrm{\&psi;}}_0=\arctan (-\frac{T_{12}}{T_{22}})$

θ ₀＝arcsin?T ₃₂

${\mathrm{\&gamma;}}_0=\arctan (-\frac{T_{31}}{T_{33}})$

Wherein the field of definition of grid heading angle ψ is (0 a °, 360 °); The field of definition of pitch angle θ is (90 °, 90 °); The field of definition of roll angle γ is (90 °, 90 °),

Obtain their true value by the field of definition of attitude angle, the true value at grid heading angle is

The true value of pitch angle is

θ＝θ ₀

The true value of roll angle is

2, the carrier posture measuring method that is suitable for optical fibre gyro according to claim 1, it is characterized in that: the initial position at the carrier described in the step 1 is provided by GPS device or outside high-precision integrated navigation equipment, and the initial velocity value of described carrier is provided by DVL Doppler log or outside high-precision integrated navigation equipment.

3, the carrier posture measuring method that is suitable for optical fibre gyro according to claim 1 and 2, it is characterized in that: the initial attitude in the relative navigation coordinate of the carrier described in the step 2 system determines to be divided into two kinds of situations: when carrier is in quiet pedestal, adopt the Alignment Method based on classic control theory; When carrier is in moving pedestal, adopt combination alignment methods based on kalman filtering theory.

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