CN103175528B - Strap-down compass gesture measurement method based on strap-down inertial navigation system - Google Patents

Abstract

The invention provides a strap-down compass gesture measurement method based on a strap-down inertial navigation system. The method utilizes information of a set of inertial measurement assembly comprising an accelerometer and a gyroscope, the procedures of the strap-down inertial navigation system and a strap-down compass system run in a navigation computer, a strap-down inertial navigation system mathematics platform and a strap-down compass system mathematics platform are respectively established, and the influences of speeds, latitude compensation ship speeds, latitudes and accelerations on the strap-down compass system are output via the strap-down inertial navigation system. According to the method provided by the invention, no external speed reference device such as an electromagnetic log and a doppler log are needed, so that the cost is low and the use is convenient.

Description

Based on the strapdown compass attitude measurement method of strapdown inertial navitation system (SINS)

Technical field

What the present invention relates to is a kind of air navigation aid of strapdown compass.

Background technology

In marine navigator, strapdown compass system is to provide the strap-down inertial system of course and horizontal attitude.Compass system is that one utilizes compass effect principle to adjust horizontal attitude, azimuthal a kind of strap-down inertial system programme of work.Due to the existence of compass effect, so under the effect at azimuthal error angle, lateral error angle can be subject to extra impact.Compass system utilizes this kind of coupled relation, adjustment horizontal attitude, position angle.

Disperse in order to ensure course and horizontal attitude nonoscillatory, conventional strapdown compass system algorithm still continues to use platform compass principle.Under compass scheme is mainly used in quiet pedestal situation, the ratio force information recorded by accelerometer, then through compass loop, can calculate correction angle speed then calculating and correction angle speed and platform is to the component of inertial system angular speed on body axis system from inertia device institute angle measurement speed middle compensation is fallen, and finally utilizes the angular speed after compensating just can carry out attitude algorithm, the attitude information of real-time output carrier.

But in moving base situation, the calculating of correction angle speed can not be directly used in than force information, because now there is the interference of outer speed, but compass system itself can not output speed information, so we design proposal must compensate the harmful interference information of outer speed fall from than force information, and then resolve.

For this problem, comparatively traditional method has been that after compass is aimed at, from obtained course angle, direct compensation speed is on the impact in course.Certainly, also many people are had to propose new method at present, as " the Strapdown Gyro Using compass research that GPS/SINS assembled gesture resolves " that Bao Hongyang delivers on " Nantong shipping Vocationl Technical College journal ", through " the moving base self-aligned technology of strapdown compass " that Zhang Jun delivers on " Chinese inertial technology journal ".

Traditional method just compensates harmful acceleration after end is resolved in course, and the error caused is excessive, and carries out the requirement of attitude algorithm when being discontented with full; Although 2 of new proposition kinds of methods, resolving the harmful acceleration of precompensation, have all relied on the external unit such as GPS or log, due to the impact of some other factorses such as asynchronous sampling and equipment instability, comparatively big error can be brought.

Summary of the invention

The speed that the object of the present invention is to provide a kind of inertial navigation to export carrys out the impact of compensated acceleration, thus improves the strapdown compass attitude measurement method based on strapdown inertial navitation system (SINS) of the precision of strapdown compass system.

The object of the present invention is achieved like this:

Step 1: preheating inertial measurement cluster, described inertial measurement cluster comprises accelerometer and gyro;

Step 2: inertial measuring unit measurement data exports in real time, accelerometer exports specific force f ^b, gyro output angle speed

Step 3: under the support of same set of inertial measuring unit measurement data, in navigational computer, parallel running strapdown inertial navitation system (SINS) and strapdown compass system program set up strapdown inertial navitation system (SINS), strapdown compass system mathematical platform respectively;

Step 4: strapdown inertial navitation system (SINS) exports strapdown inertial navitation system (SINS) velocity information in real time and latitude information

Step 5: strapdown compass system degree of will speed up meter exports specific force f ^blive fluoroscopic is fastened to navigation coordinate and is obtained f ^p;

Step 6: the f that step 5 is obtained ^pcarry out real-Time Compensation, obtain f ^poffset

Step 7: utilize compass principle of work, obtained by step 6 measurement obtains strapdown compass correction angle speed omega _c;

Step 8: by step 4, the real-time output speed information of strapdown inertial navitation system (SINS) angular velocity is involved with latitude information measurement and earth rate

Step 9: strapdown compass system involves angular velocity by step 8 and earth rate live fluoroscopic to carrier coordinate system obtains

Step 10: by gyro output angle speed in step 2 in step 9 real-time measurement strapdown compass system mathematical platform rotational angular velocity

Step 11: utilize strap-down matrix corresponding to real-time resolving strapdown compass system mathematical platform;

Step 12: strapdown compass system exports attitude information in real time.

The present invention can also comprise:

1, to f ^pthe method of carrying out real-Time Compensation comprises:

$\stackrel{\‾}{f^p}=f^p-A^p$

Wherein i.e. A ^pcan be obtained by the difference of strapdown inertial navitation system (SINS) output speed.

2, angular velocity is involved and earth rate measuring process be:

Wherein [] ^trepresent transposition, with represent strapdown inertial navitation system (SINS) velocity information at east orientation and the north orientation speed component of geographic coordinate system p system, directly can be exported by strapdown inertial navitation system (SINS); for the latitude value of boats and ships locality.

Strap-down inertial system is only made up of measurement components and computing machine two parts, and strap-down inertial system has given up complicated physical platform system, replaces the effect of platform in the mode of mathematical computations.Therefore, for strap-down inertial system, due to physical platform replace by the math matrix, therefore also can need not be confined to the control method on physical platform to platform courses thought.Mathematical platform corresponding to a set of inertial measuring unit can not just one, as long as the speed of computing machine is enough fast, the measurement data of same set of inertial measuring unit can support strapdown inertial navitation system (SINS) parallel computation simultaneously.Separate computing between each system, different systems is due to operational method difference, and the navigation results so carried out based on respective mathematical platform also respectively will have feature.Effectively utilize their response variances to same error source, can the error of reverse observing system, and the error of each system is compensated.

In vessel motion process, if need to carry out initial alignment, so just need to consider unexistent outer acceleration noise in static-base alignment situation.

Disturb about outer speed, the strapdown inertial navitation system (SINS) under same set of inertial measuring unit and strapdown compass system can be utilized to share a set of property measurement mechanism and to export the data characteristic that makes error less, the information such as the speed exported by strapdown inertial navitation system (SINS) go to compensate the error in strapdown compass system, so just can reach good effect with less error.Can be directly right carry out Difference Calculation gained and be harmful to carrier acceleration A ^p.

Finally, the harmful acceleration A calculated ^pcompensate to the acceleration measurement f of strapdown compass ^pin, then carry out attitude algorithm.

The invention provides a kind of compensation method based on strap-down inertial and strapdown compass dual system.While compass system runs, the a set of strapdown inertial navitation system (SINS) of parallel computation, two cover systems share an inertial measurement component, separate computing between each system, different systems is due to operational method difference, and the navigation results so carried out based on respective mathematical platform also respectively will have feature.Effectively utilize their response variances to same error source, can the error of reverse observing system, and the error of each system is compensated.Carry out the impact of compensated acceleration by the speed that inertial navigation exports, thus improve the precision of strapdown compass system.

The present invention does not need to introduce external speed reference device, as electromagnet log, Doppler log, therefore has the advantages such as cost is low, easy to use.

Accompanying drawing explanation

Fig. 1 is that in the present invention, strapdown compass system resolves schematic diagram.

Fig. 2 is schematic diagram of the present invention.

Fig. 3 is dual system concurrent operation schematic diagram of the present invention.

Embodiment

Below in conjunction with Fig. 1 citing, the present invention is described in more detail:

The coordinate system that the present invention relates to has: p-mathematical platform coordinate system; B-carrier coordinate system.Conversion between two coordinate systems represents with direction cosine matrix.

1, inertial measurement cluster (comprising accelerometer and gyro) preheating, preheating time can see operation instructions;

2, inertial measuring unit measurement data exports in real time, and accelerometer exports specific force f ^b, gyro output angle speed

3, under the support of same set of inertial measuring unit measurement data, in navigational computer, parallel running strapdown inertial navitation system (SINS) and strapdown compass system program set up strapdown inertial navitation system (SINS), strapdown compass system mathematical platform respectively;

4: strapdown inertial navitation system (SINS) exports strapdown inertial navitation system (SINS) velocity information in real time and latitude information

5: strapdown compass system degree of will speed up meter exports specific force f ^blive fluoroscopic is fastened to navigation coordinate and is obtained f ^p;

$f^p=C_b^p{f}^b$

Wherein for the strap-down matrix of mathematical platform real-time resolving in step 3;

6: the f that step 5 is obtained ^pcarry out real-Time Compensation, obtain f ^poffset

$\stackrel{\‾}{f^p}=f^p-A^p$

Wherein i.e. A ^pcan be obtained by the difference of strapdown inertial navitation system (SINS) output speed;

7, utilize compass principle of work, obtained by step 6 measurement obtains strapdown compass correction angle speed omega _c;

8, by step 4, the real-time output speed information of strapdown inertial navitation system (SINS) angular velocity is involved with latitude information measurement and earth rate

Wherein [] ^trepresent transposition, represent strapdown inertial navitation system (SINS) velocity information at east orientation and the north orientation speed component of geographic coordinate system p system, directly can be exported by strapdown inertial navitation system (SINS); for the latitude value of boats and ships locality;

9: strapdown compass system involves angular velocity by step 8 and earth rate live fluoroscopic to carrier coordinate system obtains with

${\mathrm{\ω}}_{\mathrm{ep}}^b+{\mathrm{\ω}}_{\mathrm{ie}}^b=C_p^b({\mathrm{\ω}}_{\mathrm{ep}}^p+{\mathrm{\ω}}_{\mathrm{ie}}^p)$

$C_p^b=[C_b^p{]}^T;$

10: by gyro output angle speed in step 2 in step 9 real-time measurement strapdown compass system mathematical platform rotational angular velocity

${\mathrm{\ω}}_{\mathrm{pb}}^b={\mathrm{\ω}}_{\mathrm{ib}}^b-{\mathrm{\ω}}_c^b-({\mathrm{\ω}}_{\mathrm{ep}}^b+{\mathrm{\ω}}_{\mathrm{ie}}^b);$

11: utilize strap-down matrix corresponding to real-time resolving strapdown compass system mathematical platform;

12: strapdown compass system exports attitude information in real time.

Claims (3)

1., based on a strapdown compass attitude measurement method for strapdown inertial navitation system (SINS), it is characterized in that comprising the steps:

Step 1: preheating inertial measurement cluster, described inertial measurement cluster comprises accelerometer and gyro;

Step 2: inertial measurement cluster measurement data exports in real time, accelerometer exports specific force f ^b, gyro output angle speed

Step 3: under the support of same set of inertial measurement cluster measurement data, in navigational computer, parallel running strapdown inertial navitation system (SINS) and strapdown compass system program set up strapdown inertial navitation system (SINS), strapdown compass system mathematical platform respectively;

Step 4: strapdown inertial navitation system (SINS) exports strapdown inertial navitation system (SINS) velocity information in real time and latitude information

Step 5: strapdown compass system degree of will speed up meter exports specific force f ^blive fluoroscopic is fastened to navigation coordinate and is obtained f ^p;

Step 6: the f that step 5 is obtained ^pcarry out real-Time Compensation, obtain f ^poffset

Step 7: utilize compass principle of work, obtained by step 6 measurement obtains strapdown compass correction angle speed omega _c;

Step 8: by step 4, the real-time output speed information of strapdown inertial navitation system (SINS) angular velocity is involved with latitude information measurement and earth rate

Step 9: strapdown compass system involves angular velocity by step 8 and earth rate live fluoroscopic to carrier coordinate system obtains with

Step 10: by gyro output angle speed in step 2 in step 9 with real-time measurement strapdown compass system mathematical platform rotational angular velocity

Step 11: utilize strap-down matrix corresponding to real-time resolving strapdown compass system mathematical platform;

Step 12: strapdown compass system exports attitude information in real time.

2. the strapdown compass attitude measurement method based on strapdown inertial navitation system (SINS) according to claim 1, is characterized in that f ^pthe method of carrying out real-Time Compensation comprises:

$\stackrel{\‾}{f^p}=f^p-A^p$

Wherein i.e. A ^pcan be obtained by the difference of strapdown inertial navitation system (SINS) output speed.

3. the strapdown compass attitude measurement method based on strapdown inertial navitation system (SINS) according to claim 1 and 2, is characterized in that involving angular velocity and earth rate measuring process be:

Wherein [] ^trepresent transposition, with represent strapdown inertial navitation system (SINS) velocity information at east orientation and the north orientation speed component of geographic coordinate system p system, directly can be exported by strapdown inertial navitation system (SINS); for the latitude value of boats and ships locality.