CN102706349A - Carrier gesture determining method based on optical fiber strap-down compass technology - Google Patents

Abstract

The invention provides a carrier gesture determining method based on an optical fiber strap-down compass technology. The method comprises the following steps of: when a carrier is in a mobile environment and output of an accelerometer contains a large quantity of disturbing acceleration, filtering the disturbing acceleration of the carrier by using a digital low-pass filter, then observing slow drift of gravitational potential acceleration due to rotation of the earth in an inertial coordinate system, determining geographical north information by analyzing the motion of gravity acceleration, determining a gesture strap-down matrix of the system, and calculating gesture information of the carrier at any moment. By the method, influence of the Schuler oscillation period and the Foucault oscillation period which are included in the output posture information in the conventional gesture measuring method on gesture precision of the system is effectively eliminated; and the method has the characteristics of autonomy and high precision, and is applied to various strap-down inertial navigation systems with medium and high precision.

Description

A kind of attitude of carrier based on fiber strapdown compass technology is confirmed method

(1) technical field

What the present invention relates to is a kind of measuring method, and in particular a kind of attitude of carrier based on fiber strapdown compass technology is confirmed method.

(2) background technology

Traditional gyrocompass is that the most ancient gyro with a high speed rotating is a basic system; Can make its square direction of wrestling consistent, just as the magnetic torque and the terrestrial magnetic field direction of the magnetic compass that kind that is consistent confirms that geographic north is to relevant orientation with the geocyclic square direction of wrestling.From nineteen twenties, this gyrocompass just is applied on all kinds of naval vessels always, and these naval vessels need the course precision in several years at zero point and can avoid magnetic interference.In the past six in a decade or so in, this technology has no variation on basic principle, simultaneously in use its also needs very careful maintenance, and the reliability that provides is also limited.Gyro compass system must be able to bear the influence of random motion, and promptly no matter how carrier moves, and gyrocompass must keep motion relative insensitivity to external world, and this random motion possibly be very violent, like the rolling of ship, wave, the springing up etc. of wave.So consider actual abominable movement environment, we can clearly know: because the existence of motions such as rolling, waves is arranged, the measured earth rate of gyro receives the interference of very large amount of spin; Secondly, when receiving the motion of automobile such as wave springs up, carrier acceleration and deceleration, the acceleration of gravity of accelerometer measures receives the interference of centrifugal acceleration and convected acceleration, and centrifugal acceleration is proved to be quite high.The tradition gyro compass system directly utilizes the measurement of the earth slewing rate relevant with gyro gimbal, the special advantage of this way nothing, and also systematic comparison is complicated, does not meet the requirement of fiber strapdown compass system.

Fibre optic gyroscope is big with its dynamic range, precision is high, startup is fast and system design is flexible etc., and advantage obtains fast development and application in the inertia device field.Fibre optic gyroscope can be in any setting instantaneous, measure the angular velocity of rotation of moving object, acceleration measuring measures the summation of gravity apparent acceleration He other acceleration of carrier.These metrical informations are all relevant with the reference frame of moving object self, and motion carrier can calculate through the integration of angular velocity of rotation with respect to the angle attitude of inertial space.If the centrifugal acceleration of carrier and convected acceleration etc. are weeded out, in inertial coordinates system, just can observe so because the slow drift of the gravity apparent acceleration that earth rotation causes.If in inertial coordinates system, observe acceleration of gravity, its movement locus constitutes a circular conical surface so, and this cone main shaft is the turning axle of the earth.Therefore if get the projection of acceleration of gravity at inertial coordinates system, then its projection components just can comprise rotational-angular velocity of the earth information, can confirm that just geographic north is to information so only need analyze the motion of acceleration of gravity.

(3) summary of the invention

Technology of the present invention is dealt with problems and is: overcome the prior art deficiency; Provide a kind of wave digital lowpass filter that utilizes to ask for the acceleration of gravity information under the inertial coordinates system; In inertial system, carry out the motion state that the relative earth surface of carrier is obtained in projection by acceleration of gravity, realize the new method that the attitude of carrier information real-time is obtained.

Technical solution of the present invention is: a kind of attitude of carrier based on fiber strapdown compass technology is confirmed method; It is characterized in that carrier is under the motor-driven environment; Comprising a large amount of disturbing accelerations in the accelerometer output; After utilizing wave digital lowpass filter filtering carrier disturbing acceleration; In inertial coordinates system, just can observe because the slow drift of the gravity apparent acceleration that earth rotation causes; Motion through analyzing acceleration of gravity just can be confirmed geographic north to information, realizes the obtaining of attitude of carrier information comprised the influence to attitude accuracy of Schuler period concussion and Foucault periodic vibration error in the attitude information of having avoided traditional SINS to ask for simultaneously with this.Its concrete steps are following:

(1) utilizes global position system GPS to confirm the initial position parameters of carrier, they are bound to navigational computer;

(2) fiber optic gyro strapdown inertial navigation system carries out preheating, gathers the data of fibre optic gyroscope and quartz accelerometer output then;

(3) fibre optic gyroscope that collects and the data of quartz accelerometer are handled;

(4) the carrier of three accelerometers measuring acceleration?

Convert to get on inertial acceleration?

${\tilde{f}}^i=C_b^i{\tilde{f}}^b$

Wherein,

expression carrier coordinate system is to the transition matrix of inertial coordinates system; According to gyrostatic output; Utilize the hypercomplex number method that matrix

is carried out real-time update, for the computing of following one-period provides parameter; Comprise two parts in

: gravity acceleration g and other acceleration (harmful acceleration and Maneuver Acceleration).Harmful acceleration and Maneuver Acceleration also will change very violent in inertial system because of

, change frequency range and be in than higher frequency; Gravity acceleration g is made circular cone slow-drift motion (like accompanying drawing 2) in inertial system, change very slowly, and the cycle changed frequency range and is in lower frequency about 20 hours.

(5) the design low-pass filter is realized obtaining acceleration of gravity.

The design low-pass filter is taken all factors into consideration factors such as low-pass characteristic, time-delay size, and the transitional zone of setting filtering accelerometer signal wave filter is respectively [0.01Hz, 0.02Hz].

Utilize acceleration of gravity information to demonstrate slow circular cone and change this characteristic, take low-pass filtering technique the acceleration information under the inertial system in the pedestal inertial system

Handle, the filtering carrier obtains pure relatively gravity acceleration g owing to wave and swing the disturbance angle velocity and the acceleration of motion generation ⁱ, it obtains flow process such as accompanying drawing 3.

(6) with the acceleration of gravity information g that obtains ⁱIn inertial system, carry out projection

Calculate α, β by projection.

$\mathrm{\α}={\tan }^{-1}(g_x^i/g_y^i)$

$\mathrm{\β}={\tan }^{-1}(g_z^i/\sqrt{g_y^{i^2}+g_x^{i^2}})$

The rotation matrix of being confirmed by α, β is respectively:

$\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000730864300022.png"\; state="\{\{state\}\}">C</figure-callout>}1=\left[\begin{array}{ccc}\cos \mathrm{\&alpha;}& \sin \mathrm{\&alpha;}& 0\\ -\sin \mathrm{\&alpha;}& \cos \mathrm{\&alpha;}& 0\\ 0& 0& 1\end{array}\right]$

$\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HSA00000730864300022.png"\; state="\{\{state\}\}">C</figure-callout>}2=\left[\begin{array}{ccc}1& 0& 0\\ 0& \sin \mathrm{\&beta;}& \cos \mathrm{\&beta;}\\ 0& -\cos \mathrm{\&beta;}& \sin \mathrm{\&beta;}\end{array}\right]$

Can obtain the transformation matrix

between inertial system and the Department of Geography by C1, C2

$C_i^n=C2\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000730864300022.png"\; state="\{\{state\}\}">C</figure-callout>}1$

The angular velocity that is obtained by gyro carries out real-time update to

and obtains in inertial space:

${\stackrel{\&CenterDot;}{C}}_b^i=C_b^i{\mathrm{\&Omega;}}_{\mathrm{ib}}^b$

Wherein,

is the antisymmetric matrix of

.Through above-mentioned real-time calculating, the strapdown matrix

between Department of Geography and carrier system

$C_b^n=C_i^n{C}_b^i=\left[\begin{array}{ccc}{C}_{11}^n& C_{12}^n& C_{13}^n\\ C_{21}^n& C_{22}^n& C_{23}^n\\ C_{31}^n& C_{32}^n& C_{33}^n\end{array}\right]$

Again because

Therefore, according to strapdown matrix? to determine carrier heading angle?

pitch angle θ, the tilt angle γ principal value:

Course angle

field of definition is (0 °; 360 °); The pitching angle theta field of definition is (90 °, 90 °), and pitch angle γ field of definition is (180 °; 180 °), obtain the attitude of carrier true value:

θ=θ _Main

The present invention's advantage compared with prior art is: the present invention has broken and has comprised Schuler concussion cycle, Foucault concussion cycle in the attitude of carrier information that adopts conventional calculation to ask in the inertial navigation system and cause the situation that system can't accurate description carrier movement characteristic; Through utilizing the disturbing acceleration information that comprises in the output of wave digital lowpass filter filtering accelerometer; Obtain the acceleration of gravity under the inertial system; Motion through analyzing acceleration of gravity can confirm that just geographic north is to information; Owing to do not adopt traditional attitude of carrier computing method, therefore avoided the existence in system's concussion cycle, realize accurately obtaining with this to attitude of carrier information.

Effect to the present invention is useful is explained as follows:

The attitude of carrier information getting method that adopts the present invention to propose based on strapdown compass scheme; Attitude information on three directions of the carrier that calculates is compared with the attitude information that reference data PHINS provides respectively, and error amount is in effective range (like accompanying drawing 4) all.

(4) description of drawings

Fig. 1 confirms method flow diagram for the attitude of carrier based on fiber strapdown compass technology of the present invention;

Fig. 2 obtains flow process for inertial system terrestrial gravitation acceleration of the present invention;

Fig. 3 is a change in gravitational acceleration trend map of the present invention;

Fig. 4 is the attitude correlation curve of compass method of the present invention (ADS) and reference data PHINS;

(5) embodiment

Describe in detail below in conjunction with the accompanying drawing specific embodiments of the invention:

(1) utilizes global position system GPS to confirm the initial position parameters of carrier, they are bound to navigational computer;

(2) fiber optic gyro strapdown inertial navigation system carries out preheating, gathers the data of fibre optic gyroscope and quartz accelerometer output then;

(3) fibre optic gyroscope that collects and the data of quartz accelerometer are handled;

(4) the carrier of three accelerometers measuring acceleration?

convert to get on inertial acceleration?

${\tilde{f}}^i=C_b^i{\tilde{f}}^b$

Wherein,

expression carrier coordinate system is to the transition matrix of inertial coordinates system; According to gyrostatic output; Utilize the hypercomplex number method that matrix

is carried out real-time update, for the computing of following one-period provides parameter; Comprise two parts in

: gravity acceleration g and other acceleration (harmful acceleration and Maneuver Acceleration).Harmful acceleration and Maneuver Acceleration also will change very violent in inertial system because of

, change frequency range and be in than higher frequency; Gravity acceleration g is made circular cone slow-drift motion (like accompanying drawing 2) in inertial system, change very slowly, and the cycle changed frequency range and is in lower frequency about 20 hours.

(5) the design low-pass filter is realized obtaining acceleration of gravity.

The design low-pass filter is taken all factors into consideration factors such as low-pass characteristic, time-delay size, and the transitional zone of setting filtering accelerometer signal wave filter is respectively [0.01Hz, 0.02Hz].

Utilize acceleration of gravity information to demonstrate slow circular cone and change this characteristic, take low-pass filtering technique the acceleration information under the inertial system in the pedestal inertial system

Handle, the filtering carrier obtains pure relatively gravity acceleration g owing to wave and swing the disturbance angle velocity and the acceleration of motion generation ⁱ, it obtains flow process such as accompanying drawing 3.

(6) with the acceleration of gravity information g that obtains ⁱIn inertial system, carry out projection

Calculate α, β by projection.

$\mathrm{\&alpha;}={\tan }^{-1}(g_x^i/g_y^i)---\left(2\right)$

$\mathrm{\&beta;}={\tan }^{-1}(g_z^i/\sqrt{g_y^{i^2}+g_x^{i^2}})---\left(3\right)$

The rotation matrix of being confirmed by α, β is respectively:

$\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000730864300022.png"\; state="\{\{state\}\}">C</figure-callout>}1=\left[\begin{array}{ccc}\cos \mathrm{\&alpha;}& \sin \mathrm{\&alpha;}& 0\\ -\sin \mathrm{\&alpha;}& \cos \mathrm{\&alpha;}& 0\\ 0& 0& 1\end{array}\right]---\left(4\right)$

$\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HSA00000730864300022.png"\; state="\{\{state\}\}">C</figure-callout>}2=\left[\begin{array}{ccc}1& 0& 0\\ 0& \sin \mathrm{\&beta;}& \cos \mathrm{\&beta;}\\ 0& -\cos \mathrm{\&beta;}& \sin \mathrm{\&beta;}\end{array}\right]---\left(5\right)$

Can obtain the transformation matrix

between inertial system and the Department of Geography by C1, C2

$C_i^n=C2C1---\left(6\right)$

The angular velocity that is obtained by gyro carries out real-time update to

and obtains in inertial space:

${\stackrel{\&CenterDot;}{C}}_b^i=C_b^i{\mathrm{\&Omega;}}_{\mathrm{ib}}^b---\left(7\right)$

Wherein,

is the antisymmetric matrix of

.Through above-mentioned real-time calculating, the strapdown matrix between Department of Geography and carrier system

$C_b^n=C_i^n{C}_b^i=\left[\begin{array}{ccc}{C}_{11}^n& C_{12}^n& C_{13}^n\\ C_{21}^n& C_{22}^n& C_{23}^n\\ C_{31}^n& C_{32}^n& C_{33}^n\end{array}\right]---\left(8\right)$

Again because

Therefore, according to strapdown matrix? to determine carrier heading angle?

pitch angle θ, the tilt angle γ principal value:

Course angle

field of definition is (0 °; 360 °); The pitching angle theta field of definition is (90 °, 90 °), and pitch angle γ field of definition is (180 °; 180 °), obtain the attitude of carrier true value:

θ=θ _Main(12)

。

Claims (4)

1. the attitude of carrier based on fiber strapdown compass technology is confirmed method, it is characterized in that may further comprise the steps:

(1) utilizes global position system GPS to confirm the initial position parameters of carrier, they are bound to navigational computer;

(2) fiber optic gyro strapdown inertial navigation system carries out preheating, gathers the data of fibre optic gyroscope and quartz accelerometer output then;

(3) fibre optic gyroscope that collects and the data of quartz accelerometer are handled;

(4) the carrier of three accelerometers measuring acceleration?

convert to get on inertial acceleration?

Wherein, expression carrier coordinate system is to the transition matrix of inertial coordinates system; According to gyrostatic output; Utilize the hypercomplex number method that matrix

is carried out real-time update, for the computing of following one-period provides parameter; Comprise two parts in

: gravity acceleration g and other acceleration (harmful acceleration and Maneuver Acceleration).Harmful acceleration and Maneuver Acceleration also will change very violent in inertial system because of

, change frequency range and be in than higher frequency; Gravity acceleration g is made circular cone slow-drift motion (like accompanying drawing 2) in inertial system, change very slowly, and the cycle changed frequency range and is in lower frequency about 20 hours.

(5) the design low-pass filter is realized obtaining acceleration of gravity.

The design low-pass filter is taken all factors into consideration factors such as low-pass characteristic, time-delay size, and the transitional zone of setting filtering accelerometer signal wave filter is respectively [0.01Hz, 0.02Hz].

Utilize acceleration of gravity information to demonstrate slow circular cone and change this characteristic, take low-pass filtering technique the acceleration information under the inertial system in the pedestal inertial system

Handle, the filtering carrier obtains pure relatively gravity acceleration g owing to wave and swing the disturbance angle velocity and the acceleration of motion generation ⁱ, it obtains flow process such as accompanying drawing 3.

(6) with the acceleration of gravity information g that obtains ⁱIn inertial system, carry out projection

Calculate α, β by projection.

The rotation matrix of being confirmed by α, β is respectively:

Can obtain the transformation matrix

between inertial system and the Department of Geography by C1, C2

The angular velocity that is obtained by gyro carries out real-time update to

and obtains in inertial space:

Wherein, is the antisymmetric matrix of

.Through above-mentioned real-time calculating, the strapdown matrix

between Department of Geography and carrier system

Again because

Therefore, according to strapdown matrix?

to determine carrier heading angle?

pitch angle θ, the tilt angle γ principal value:

Course angle

field of definition is (0 °; 360 °); The pitching angle theta field of definition is (90 °, 90 °), and pitch angle γ field of definition is (180 °; 180 °), obtain the attitude of carrier true value:

θ=θ _Main

。

2. a kind of attitude of carrier based on fiber strapdown compass technology according to claim 1 is confirmed method, it is characterized in that described carrier acceleration with three accelerometer measures

is transformed into to obtain acceleration

on the inertial system

Wherein,

expression carrier coordinate system is to the transition matrix of inertial coordinates system; According to gyrostatic output; Utilize the hypercomplex number method that matrix

is carried out real-time update, for the computing of following one-period provides parameter; Comprise two parts in

: gravity acceleration g and other acceleration (harmful acceleration and Maneuver Acceleration).Harmful acceleration and Maneuver Acceleration also will change very violent in inertial system because of , change frequency range and be in than higher frequency; Gravity acceleration g is made the circular cone slow-drift motion in inertial system, change very slowly, and the cycle changed frequency range and is in lower frequency about 20 hours.

3. a kind of attitude of carrier based on fiber strapdown compass technology according to claim 1 is confirmed method, it is characterized in that described design low-pass filter realization obtaining acceleration of gravity;

The design low-pass filter is taken all factors into consideration factors such as low-pass characteristic, time-delay size, and the transitional zone of setting filtering accelerometer signal wave filter is respectively [0.01Hz, 0.02Hz].

Utilize acceleration of gravity information to demonstrate slow circular cone and change this characteristic, take low-pass filtering technique the acceleration information under the inertial system in the pedestal inertial system

Handle, the filtering carrier obtains pure relatively gravity acceleration g owing to wave and swing the disturbance angle velocity and the acceleration of motion generation ⁱ

4. a kind of attitude of carrier based on fiber strapdown compass technology according to claim 1 is confirmed method, it is characterized in that described with the acceleration of gravity information g that obtains ⁱIn inertial system, carry out projection

Calculate α, β by projection;

The rotation matrix of being confirmed by α, β is respectively:

Can obtain the transformation matrix

between inertial system and the Department of Geography by C1, C2

The angular velocity that is obtained by gyro carries out real-time update to and obtains in inertial space:

Wherein,

is the antisymmetric matrix of .Through above-mentioned real-time calculating, the strapdown matrix

between Department of Geography and carrier system

Again because

Therefore, according to strapdown matrix? to determine carrier heading angle?

pitch angle θ, the tilt angle γ principal value:

Course angle

field of definition is (0 °; 360 °); The pitching angle theta field of definition is (90 °, 90 °), and pitch angle γ field of definition is (180 °; 180 °), obtain the attitude of carrier true value:

θ=θ _Main

。

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