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

Abstract

The invention provides a strapdown compass attitude measurement method based on a strapdown inertial navigation system. Using a set of inertial measurement component information, the inertial measurement component includes an accelerometer and a gyroscope, run the strapdown inertial navigation system and the strapdown compass system program in the navigation computer, and respectively establish the strapdown inertial navigation system and the strapdown compass system mathematics The platform uses the strapdown inertial navigation system to output speed and latitude to compensate the influence of ship speed, latitude and acceleration on the strapdown compass system. The method of the invention does not need to introduce external speed reference equipment, such as electromagnetic log and Doppler log, so it has the advantages of low cost and convenient use.

Description

Strapdown Compass Attitude Measurement Method Based on Strapdown Inertial Navigation System

technical field

The invention relates to a navigation method of a strapdown compass.

Background technique

In ship navigation systems, the strapdown compass system is a strapdown inertial system that provides heading and horizontal attitude. The compass system is a strapdown inertial system working scheme that uses the principle of compass effect to adjust the horizontal attitude and azimuth. Due to the existence of the compass effect, the horizontal error angle will be additionally affected by the azimuth error angle. The compass system uses this coupling relationship to adjust the horizontal attitude and azimuth.

In order to ensure that the heading and horizontal attitude do not oscillate and diverge, the commonly used strapdown compass system algorithm still uses the platform compass principle. The compass scheme is mainly used in the case of a static base, through the specific force information measured by the accelerometer, and then through the compass loop, the corrected angular rate can be calculated Then take the calculated and corrected angular rate And the component of the angular rate of the platform to the inertial system on the body coordinate system Angular rate measured from inertial device Compensate in the center, and finally use the compensated angular rate to calculate the attitude, and output the attitude information of the carrier in real time.

However, in the case of a moving base, the specific force information cannot be directly used for the calculation of the corrected angular rate, because there is interference from the external velocity at this time, but the compass system itself cannot output velocity information, so we must design a plan to incorporate the external velocity The harmful interference information is compensated from the comparison information, and then the solution is performed.

To solve this problem, the more traditional method is to directly compensate the influence of speed on the heading from the obtained heading angle after compass alignment is completed. Of course, many people have proposed new methods at present, such as Bao Hongyang's "GPS/SINS combined attitude calculation strapdown gyrocompass research" published in "Journal of Nantong Vocational and Technical College of Shipping", Zhang Jun in "China Inertial "Automatic base self-alignment technology of strapdown compass" published in "Technical Journal".

The traditional method compensates for the harmful acceleration after the heading calculation is completed, which causes too much error and does not meet the requirements of real-time attitude calculation; although the two new methods compensate the harmful acceleration before the calculation, they both rely on If external equipment such as GPS or log is used, due to the influence of other factors such as sampling asynchrony and equipment instability, it will bring large errors.

Contents of the invention

The purpose of the present invention is to provide a strapdown inertial navigation system-based strapdown compass attitude measurement method that uses the speed output by the strapdown inertial navigation system to compensate the influence of acceleration, thereby improving the accuracy of the strapdown compass system.

The purpose of the present invention is achieved like this:

Step 1: preheating the inertial measurement assembly, which includes an accelerometer and a gyroscope;

Step 2: Real-time output of the measurement data of the inertial measurement device, the accelerometer outputs the specific force f ^b , and the gyroscope outputs the angular velocity

Step 3: With the support of the measurement data of the same set of inertial measurement devices, run the SINS and SINS programs in parallel in the navigation computer to establish the SINS and SINS mathematical platforms respectively;

Step 4: Strapdown inertial navigation system outputs speed information of strapdown inertial navigation system in real time and latitude information

Step 5: The strapdown compass system projects the output specific force f ^b of the accelerometer onto the navigation coordinate system in real time to obtain f ^p ;

Step 6: Compensate the f ^p obtained in step 5 in real time to obtain the compensation value of f ^p

Step 7: Using the working principle of the compass, obtained from step 6 Measure the strapdown compass correction angular velocity ω _c ;

Step 8: From step 4, the strapdown inertial navigation system outputs speed information in real time and latitude information to measure the implicated angular velocity and the Earth's angular velocity

Step 9: The strapdown compass system will involve the angular velocity in step 8 and the Earth's angular velocity Real-time projection onto the carrier coordinate system to get

Step 10: Output the angular velocity from the gyroscope in step 2 step 9 Real-time measurement of rotational angular velocity of mathematical platform of strapdown compass system

Step 11: Leverage Real-time calculation of the strapdown matrix corresponding to the math platform of the strapdown compass system;

Step 12: Strapdown compass system outputs attitude information in real time.

The present invention may also include:

1. The methods for real-time compensation of ^fp include:

$\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; f</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; f</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; A</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}$

in That is, A ^p can be obtained from the difference of the output speed of the strapdown inertial navigation system.

2. The implicated angular velocity and the Earth's angular velocity The measurement process is:

where [] ^T means transpose, and Indicates the speed information of the SINS The eastward and northward velocity components in the geographic coordinate system p can be directly output by the strapdown inertial navigation system; is the local latitude value of the ship.

The strapdown inertial system is only composed of two parts: measurement components and a computer. The strapdown inertial system abandons the complex physical platform system and replaces the role of the platform with mathematical calculations. Therefore, for the strapdown inertial system, since the physical platform is replaced by a mathematical matrix, the idea of platform control does not need to be limited to the control method on the physical platform. There may be more than one mathematical platform corresponding to a set of inertial measurement devices. As long as the computer is fast enough, the measurement data of the same set of inertial measurement devices can simultaneously support the parallel calculation of the strapdown inertial navigation system. Each system operates independently of each other, and different systems have different calculation methods, so the navigation results based on their respective mathematical platforms will also have their own characteristics. By effectively using their response deviations to the same error source, the errors of the systems can be observed inversely and the errors of each system can be compensated.

During the operation of the ship, if an initial alignment is required, it is necessary to consider the external acceleration disturbance that does not exist in the case of static base alignment.

Regarding the external velocity interference, the strapdown inertial navigation system and the strapdown compass system under the same set of inertial measurement devices can share the output data of a set of measurement devices so that the error is small, and the speed and other information output by the strapdown inertial navigation system can be used. To compensate the error in the strapdown compass system, so that a better effect can be achieved with a smaller error. can directly Harmful carrier acceleration A ^p obtained by differential calculation.

Finally, the calculated harmful acceleration A ^p is compensated to the measured acceleration f ^p of the strapdown compass, and then the attitude is calculated.

The invention provides a compensation method based on dual systems of strapdown inertial navigation and strapdown compass. While the compass system is running, a set of strapdown inertial navigation system is calculated in parallel. The two systems share an inertial measurement element, and each system operates independently of each other. Different systems have different calculation methods, so based on their respective mathematical platforms. The navigation results of will also have their own characteristics. By effectively using their response deviations to the same error source, the errors of the systems can be observed inversely and the errors of each system can be compensated. Use the speed output by the strapdown inertial navigation to compensate the influence of acceleration, thereby improving the accuracy of the strapdown compass system.

The present invention does not need to introduce external speed reference equipment, such as electromagnetic log and Doppler log, so it has the advantages of low cost and convenient use.

Description of drawings

Fig. 1 is a schematic diagram of the solution of the strapdown compass system in the present invention.

Fig. 2 is a schematic diagram of the present invention.

FIG. 3 is a schematic diagram of the dual system parallel operation of the present invention.

Detailed ways

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

The coordinate systems involved in the present invention include: p-mathematical platform coordinate system; b-carrier coordinate system. The transformation between two coordinate systems is represented by a direction cosine matrix.

1. Preheat the inertial measurement components (including accelerometer and gyroscope), please refer to the instruction manual for the preheating time;

2. The measurement data of the inertial measurement device is output in real time, the accelerometer outputs the specific force f ^b , and the gyroscope outputs the angular velocity

3. With the support of the measurement data of the same set of inertial measurement devices, run the SINS and SINS programs in parallel in the navigation computer to establish the SINS and SINS mathematical platforms respectively;

4: The strapdown inertial navigation system outputs the speed information of the strapdown inertial navigation system in real time and latitude information

5: The strapdown compass system projects the output specific force f ^b of the accelerometer onto the navigation coordinate system in real time to obtain f ^p ;

${\mathrm{<span\; class="notranslate">\; f</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}$

in It is the strapdown matrix calculated in real time by the mathematical platform in step 3;

6: Compensate the f ^p obtained in step 5 in real time to obtain the compensation value of f ^p

$\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; f</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; f</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; A</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}$

in That is, A ^p can be obtained from the difference of the output speed of the strapdown inertial navigation system;

7. Using the working principle of the compass, obtained from step 6 Measure the strapdown compass correction angular velocity ω _c ;

8. From step 4, the strapdown inertial navigation system outputs speed information in real time and latitude information to measure the implicated angular velocity and the Earth's angular velocity

where [] ^T means transpose, Indicates the speed information of the SINS The eastward and northward velocity components in the geographic coordinate system p can be directly output by the strapdown inertial navigation system; is the local latitude value of the ship;

9: The strapdown compass system will involve the angular velocity in step 8 and the Earth's angular velocity Real-time projection onto the carrier coordinate system to get and

${\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; ep</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; ie</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; ep</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; ie</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}{<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; ;</span>$

10: Output angular velocity from the gyroscope in step 2 step 9 Real-time measurement of rotational angular velocity of mathematical platform of strapdown compass system

${\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; pb</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; ib</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; ep</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; ie</span>}}^{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$

11: Use Real-time calculation of the strapdown matrix corresponding to the math platform of the strapdown compass system;

12: Strapdown compass system outputs 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:

$\stackrel{\&OverBar;}{f^p}=f^p-A^p$

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.