CN101881620A - Ship swaying and surging information measuring method based on optical fiber gyro inertial measuring system - Google Patents

Abstract

The invention aims to provide a ship swaying and surging information measuring method based on an optical fiber gyro inertial measuring system, which comprises the following steps of: collecting the output signals of an optical fiber gyro and an accelerometer in real time to obtain ship real-time attitude information to form a relational matrix of a carrier coordinate system and a geographic coordinate system, obtaining a transition matrix between the carrier coordinate system and a semifixed coordinate system through the main course angle of a ship, obtaining the ship real-time velocity information on the geographic coordinate system at an nth sampling point by utilizing the output signals, obtaining the velocity information on the x axis and the y axis of the semifixed coordinate system at the nth sampling point through coordinate conversion, integrating the velocity information to obtain the total displacement amount under the semifixed coordinate system at the nth sampling point and the total displacement amount on the x axis under the semifixed coordinate system, and filtering the displacement amounts to obtain the surging information and the swaying information of the ship. The invention not only increases the functions of an original inertial measuring system and simultaneously can improve the navigational parameter measurement accuracy of the system.

Description

Boats and ships method for measuring swaying and surging information based on optical fiber gyroscope inertial measurement system

Technical field

What the present invention relates to is a kind of method of measuring boats and ships swaying, surge motion.

Background technology

The inertial measurement system of using in the boats and ships is made up of gyroscope, accelerometer and navigational computer, and it can provide attitude, speed and the displacement information of boats and ships.The displacement of boats and ships decomposes by frequency field and can divide for by the low frequency component of the motor-driven introducing of boats and ships (boats and ships motor-driven comparatively mild), and the high fdrequency component with three degree of freedom that is caused by surge.In conventional inertia navigation measuring technique, inertial measurement system is comparatively accurate for the measurement that displacement information is measured the medium-high frequency component, and for low frequency component measuring error big (owing to having 84.4 minutes shura circular error in the low frequency component of system).

Displacement information is measured the medium-high frequency component and is caused by surge, comprises the three degree of freedom high frequency displacement information of describing ship motion, is respectively swaying (traversing), surging (vertical shift), hangs down and swing (heave).Wherein swaying (traversing) is the axial translation quantity of information along the starboard direction of boats and ships, and surging (vertical shift) is along the bow of the boats and ships axial translation quantity of information to direction.Along with developing rapidly of inertial measurement system, its measurement for three attitude informations of boats and ships (rolling, pitching, yawing) has reached higher precision, but can not provide for the high frequency displacement information on the three degree of freedom always.This is because the conventional speed measuring technique that inertial measurement system uses can only be measured the total displacement information amount of boats and ships (total displacement information amount comprises 84.4 minutes shura circular error), can not accurately isolate swaying, surging and hang down and swing high frequency displacement information amount.

Along with being extensive use of with fast-developing of inertial measurement system, inertial measurement system can not be measured the high frequency displacement information on the three degree of freedom, and the problem that especially can't measure swaying, surging translation information highlights all the more.For example: become self-aligned technology in the mooring environment of studying focus because of it is practical, it is measured immediately for swaying, surging translation informational needs; Swaying when boats and ships enter the harbour and pull in to shore, surging translation information have important reference role for ship-handling person.Needed motion state synchronous by supply boats and ships and supply boats and ships during marine ships supply goods and materials, normally and effectively work meaning is great between two boats and ships to guaranteeing make-up system to measure swaying, surging translation information.Therefore, swaying, surging translation information are as the important status information of boats and ships, and their measuring technique has important practical value for actual engineering, and the development of swaying, surging translation information measurement technology will inevitably promote the inertial measurement system development of technology.

Summary of the invention

The object of the present invention is to provide the boats and ships method for measuring swaying and surging information of measuring naval vessel swaying, surge motion under the complicated sea conditions based on optical fiber gyroscope inertial measurement system.

The object of the present invention is achieved like this:

The present invention is based on the boats and ships method for measuring swaying and surging information of optical fiber gyroscope inertial measurement system, it is characterized in that:

(1) to the abundant preheating of ship optical fiber gyroscope strap down inertial navigation system, and the output signal of gathering optical fibre gyro and accelerometer in real time;

(2) utilize the output of optical fibre gyro and accelerometer, obtain the real-time attitude information of boats and ships, comprise pitch angle α, roll angle β, yaw angle γ, constitute the relational matrix of carrier coordinate system b and geographic coordinate system t again by attitude information

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

Wherein

C ₁₁＝cosβcosγ-sinβsinαsinγ

C ₁₂＝-cosαsinγ

C ₁₃＝sinβcosγ+cosβsinαsinγ

C ₂₁＝cosβsinγ+sinβsinαcosγ

C ₂₂＝cosαcosγ；

C ₂₃＝sinβsinγ-cosβsinαcosγ

C ₃₁＝-sinβcosα

C ₃₂＝sinα

C ₃₃＝cosβcosα

The ship track of setting when (3) controlling by ship's navigation to geographic north to angle, i.e. the base course angle of boats and ships

Obtain the relational matrix that geographic coordinate system t and semi-fixed axes are d

And then to obtain carrier coordinate system b and semi-fixed axes be transition matrix between the d

(4) utilize the output of gyro and accelerometer, boats and ships real-time speed information comprises the speed on the geographic coordinate system x axle when obtaining last n the sampled point of geographic coordinate system t

Speed on the geographic coordinate system y axle

Speed on the geographic coordinate system z axle

(5) utilize matrix

Geographic coordinate system t is gone up boats and ships real-time speed information by coordinate transformation, the velocity information when obtaining semi-fixed axes and be n sampled point on the x axle

With semi-fixed axes be the velocity information during n sampled point on the y axle

(6) with semi-fixed axes be the velocity information on the x axle under the d

With the velocity information on the y axle

Carry out integration one time, total displacement when obtaining semi-fixed axes and be n sampled point under the d, promptly semi-fixed axes is a total displacement on the y axle under the d And semi-fixed axes is a total displacement on the x axle under the d

$s_y^d\left(n\right)=h\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{v}_y^d\left(k\right),$

$s_x^d\left(n\right)=h\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{v}_x^d\left(k\right)$

K=1 wherein, 2 ... n,

The expression semi-fixed axes is the velocity information during k sampled point on the x axle under the d,

The expression semi-fixed axes is the velocity information during k sampled point on the y axle under the d, With Can be when k sampled point obtained and preserved to the process measurement of step 5 by step 1, h be the sampling period of optical fiber gyroscope inertial measurement system;

(7) be displacement total under the d to the semi-fixed axes that obtains in the step (6)

With

Carry out filtering, obtain boats and ships along bow to the instant high frequency displacement of starboard direction, i.e. the surging information of boats and ships

With swaying information

${\hat{s}}_y\left(n\right)=s_y^d\left(n\right)\·\mathrm{\ω}\left(n\right),$

${\hat{s}}_x\left(n\right)=s_x^d\left(n\right)\·\mathrm{\ω}\left(n\right)$

Select the high pass digital FIR filter for use, choose kaiser window and be

$\mathrm{\ω}\left[n\right]=\frac{I_0\left[6\sqrt{1-{(\frac{2n}{N-1}-1)}^2}\right]}{70},$

Wherein function definition is

$I_0\left[x\right]=1+\underset{j=1}{\overset{20}{\mathrm{\Σ}}}{\left[\frac{{(x/2)}^j}{j!}\right]}^2,$

And have

$N=5.2\frac{f_s}{f},$

F wherein _sBe sample frequency, f is the passband edge frequency.

Advantage of the present invention is: under the situation that does not need extraneous reference information, need not to increase new sensor, utilize gyro and accelerometer output on the optical fiber gyroscope inertial measurement system that existing naval vessel installs, in conjunction with digital filtering technique, naval vessel swaying, surging information are provided in real time, not only increase original inertial measurement system function, can improve the navigational parameter measuring accuracy of system simultaneously.

Description of drawings

Fig. 1 is a process flow diagram of the present invention;

Fig. 2 is the embodiment 1 horizontal axis displacement measurement correlation when unfiltered;

Fig. 3 adopts swaying, the surge motion information that records through the inventive method for embodiment 1.

Embodiment

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

In conjunction with Fig. 1, the present invention is based on the boats and ships method for measuring swaying and surging information branch following steps of optical fiber gyroscope inertial measurement system:

(1) to the abundant preheating of ship optical fiber gyroscope strap down inertial navigation system, and the output signal of gathering optical fibre gyro and accelerometer in real time;

(2) utilize the output of optical fibre gyro and accelerometer, obtain the real-time attitude information of boats and ships, comprise pitch angle α, roll angle β, yaw angle γ, constitute the relational matrix of carrier coordinate system b and geographic coordinate system t again by attitude information

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

Wherein

C ₁₁＝cosβcosγ-sinβsinαsinγ

C ₁₂＝-cosαsinγ

C ₁₃＝sinβcosγ+cosβsinαsinγ

C ₂₁＝cosβsinγ+sinβsinαcosγ

C ₂₂＝cosαcosγ；

C ₂₃＝sinβsinγ-cosβsinαcosγ

C ₃₁＝-sinβcosα

C ₃₂＝sinα

C ₃₃＝cosβcosα

The ship track of setting when (3) controlling by ship's navigation to geographic north to angle, i.e. the base course angle of boats and ships

Obtain the relational matrix that geographic coordinate system t and semi-fixed axes are d

And then to obtain carrier coordinate system b and semi-fixed axes be transition matrix between the d

(4) utilize the output of gyro and accelerometer, boats and ships real-time speed information comprises the speed on the geographic coordinate system x axle when obtaining last n the sampled point of geographic coordinate system t

Speed on the geographic coordinate system y axle

Speed on the geographic coordinate system z axle

(5) utilize matrix Geographic coordinate system t is gone up boats and ships real-time speed information by coordinate transformation, the velocity information when obtaining semi-fixed axes and be n sampled point on the x axle

With semi-fixed axes be the velocity information during n sampled point on the y axle

(6) with semi-fixed axes be the velocity information on the x axle under the d

With the velocity information on the y axle

Carry out integration one time, total displacement when obtaining semi-fixed axes and be n sampled point under the d, promptly semi-fixed axes is a total displacement on the y axle under the d And semi-fixed axes is a total displacement on the x axle under the d

$s_y^d\left(n\right)=h\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{v}_y^d\left(k\right),$

$s_x^d\left(n\right)=h\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{v}_x^d\left(k\right)$

K=1 wherein, 2 ... n,

The expression semi-fixed axes is the velocity information during k sampled point on the x axle under the d, The expression semi-fixed axes is the velocity information during k sampled point on the y axle under the d,

With Can be when k sampled point obtained and preserved to the process measurement of step 5 by step 1, h be the sampling period of optical fiber gyroscope inertial measurement system;

(7) be displacement total under the d to the semi-fixed axes that obtains in the step (6) With

Carry out filtering, obtain boats and ships along bow to the instant high frequency displacement of starboard direction, i.e. the surging information of boats and ships

With swaying information

${\hat{s}}_y\left(n\right)=s_y^d\left(n\right)\·\mathrm{\ω}\left(n\right),$

${\hat{s}}_x\left(n\right)=s_x^d\left(n\right)\·\mathrm{\ω}\left(n\right)$

Select the high pass digital FIR filter for use, choose kaiser window and be

$\mathrm{\ω}\left[n\right]=\frac{I_0\left[6\sqrt{1-{\left(\frac{2n}{N-1}\right)}^2}\right]}{70},$

Wherein function definition is

$I_0\left[x\right]=1+\underset{j=1}{\overset{20}{\mathrm{\Σ}}}{\left[\frac{{(x/2)}^j}{j!}\right]}^2,$

And have

$N=5.2\frac{f_s}{f},$

F wherein _sBe sample frequency, f is the passband edge frequency, and the passband edge frequency f is generally had by different sea situations and identity of ship decision:

Freighter (ton) 1/8～1/13Hz,

Passenger boat (kiloton～ton) 1/9～1/15Hz.

Embodiment 1:

Utilize the periodically swaying of six degree of freedom turntable (can simulate swaying, surging, heave, rolling, pitching, yawing campaign) simulation boats and ships, surge motion.Choose the high-precision optical fiber gyro inertial measurement system, fiber-optic gyroscope strapdown inertia system device precision gyroscope constant value drift be 0.01 degree/hour, the normal at random value of accelerometer is biased to 0.0001g.On its installation and turntable table top, the simulation ship motion.Carrying out the swaying amplitude is 1 meter, 7 seconds oscillation period, and the surging amplitude is that 2 meters, the swaying of 7 seconds oscillation period, surging are measured.As Fig. 2, shown in Figure 3, experiment gained result proof is lower than 2% for the measuring result error of periodic motion, and measuring result error is expressed as

| measured value-actual value |/actual value

The difference that is measured value and actual value is divided by actual value.

Measured value tended towards stability after 3 minutes (that is to say this method need reserve 3 minutes adjustment time before measurement), and the time delay of measurement is shorter, can ignore.

Claims (1)

1. based on the boats and ships method for measuring swaying and surging information of optical fiber gyroscope inertial measurement system, it is characterized in that:

(1) to the abundant preheating of ship optical fiber gyroscope strap down inertial navigation system, and the output signal of gathering optical fibre gyro and accelerometer in real time;

(2) utilize the output of optical fibre gyro and accelerometer, obtain the real-time attitude information of boats and ships, comprise pitch angle α, roll angle β, yaw angle γ, constitute the relational matrix of carrier coordinate system b and geographic coordinate system t again by attitude information

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

Wherein

C ₁₁＝cosβcosγ-sinβsinαsinγ

C ₁₂＝-cosαsinγ

C ₁₃＝sinβcosγ+cosβsinαsinγ

C ₂₁＝cosβsinγ+sinβsinαcosγ

C ₂₂＝cosαcosγ；

C ₂₃＝sinβsinγ-cosβsinαcosγ

C ₃₁＝-sinβcosα

C ₃₂＝sinα

C ₃₃＝cosβcosα

The ship track of setting when (3) controlling by ship's navigation to geographic north to angle, i.e. the base course angle of boats and ships

Obtain the relational matrix that geographic coordinate system t and semi-fixed axes are d

And then to obtain carrier coordinate system b and semi-fixed axes be transition matrix between the d

(4) utilize the output of gyro and accelerometer, boats and ships real-time speed information comprises the speed on the geographic coordinate system x axle when obtaining last n the sampled point of geographic coordinate system t

Speed on the geographic coordinate system y axle

Speed on the geographic coordinate system z axle

(5) utilize matrix

Geographic coordinate system t is gone up boats and ships real-time speed information by coordinate transformation, the velocity information when obtaining semi-fixed axes and be n sampled point on the x axle

With semi-fixed axes be the velocity information during n sampled point on the y axle

(6) with semi-fixed axes be the velocity information on the x axle under the d

With the velocity information on the y axle

Carry out integration one time, total displacement when obtaining semi-fixed axes and be n sampled point under the d, promptly semi-fixed axes is a total displacement on the y axle under the d

And semi-fixed axes is a total displacement on the x axle under the d

$s_y^d\left(n\right)=h\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{v}_y^d\left(k\right),$

$s_x^d\left(n\right)=h\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{v}_x^d\left(k\right)$

K=1 wherein, 2 ... n, The expression semi-fixed axes is the velocity information during k sampled point on the x axle under the d,

The expression semi-fixed axes is the velocity information during k sampled point on the y axle under the d,

With

Can be when k sampled point obtained and preserved to the process measurement of step 5 by step 1, h be the sampling period of optical fiber gyroscope inertial measurement system;

(7) be displacement total under the d to the semi-fixed axes that obtains in the step (6)

With

Carry out filtering, obtain boats and ships along bow to the instant high frequency displacement of starboard direction, i.e. the surging information of boats and ships

With swaying information

${\hat{s}}_y\left(n\right)=s_y^d\left(n\right)\·\mathrm{\ω}\left(n\right),$

${\hat{s}}_x\left(n\right)=s_x^d\left(n\right)\·\mathrm{\ω}\left(n\right)$

Select the high pass digital FIR filter for use, choose kaiser window and be

$\mathrm{\ω}\left[n\right]=\frac{I_0\left[6\sqrt{1-{(\frac{2n}{N-1}-1)}^2}\right]}{70},$

Wherein function definition is

$I_0\left[x\right]=1+\underset{j=1}{\overset{20}{\mathrm{\Σ}}}{\left[\frac{{(x/2)}^j}{j!}\right]}^2,$

And have

$N=5.2\frac{f_s}{f},$

F wherein _sBe sample frequency, f is the passband edge frequency.

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