CN106123917A - Consider the SINS compass alignment methods of outer lever arm effect - Google Patents

Abstract

The present invention discloses a kind of moving base SINS compass alignment methods peculiar to vessel considering outer lever arm effect.The method is in the case of boats and ships pitching, rolling and turning, it is considered to installation site between log and SINS and the outer lever arm effect that causes, and the log thus brought tests the speed deviation being compensated in moving base compass alignment procedures.Relative to conventional moving base compass alignment methods, deviation that what the method for the present invention can calculate that outer lever arm causes effectively test the speed also is compensated for, and solves outer lever arm and causes the deviation impact for alignment performance of testing the speed.

Description

Consider the SINS compass alignment methods of outer lever arm effect

(1) technical field

The present invention relates to the Initial Alignment Method of inertial navigation system under the conditions of a kind of moving base, particularly one is deposited The moving base SINS compass alignment methods of lever arm effect outside.

(2) background technology

Inertial navigation system is before carrying out normal navigation work, it is necessary to be initially directed at.Compass alignment method is a kind of from right Quasi-method, based on " compass effect ", realizes the initial alignment of inertial navigation in conjunction with classical control theory.The compass pair of SINS The application on quiet pedestal of the quasi-technology is the most ripe, in order to meet the demand that marine strapdown inertial navigation system sea starts, promotes ship The quick-reaction capability of oceangoing ship, one of moving base compass alignment study hotspot the most having become navigation field in recent years.

Pertinent literature about inertial navigation system compass alignment is more, but the speed that log provides all thought by major part document Information is consistent with the velocity information at the IMU of SINS (IMU) present position.Wherein, typical document There is " research of naval vessel strap-down inertial system Initial Alignment Technique " (Harbin Engineering University, 2012) of Zhang Yi et al., based on quiet base What seat compass was directed at realizes principle, utilizes log as assisting navigation equipment, provides speed and the position of quiet pedestal compass alignment Put increment compensation scheme, i.e. moving base compass alignment methods.The Error Analysis and of Bo Xu et al. Compensation of Gyrocompass Alignment for SINS on Moving Base,(Mathematical Problems in Engineering, 2014), reverse navigation calculation is incorporated in moving base compass alignment, declares so may be used To shorten the alignment time.Above-mentioned two document adds with harmful at the angular velocity of rotation of computed geographical coordinates relatively spherical coordinate system During speed, it is directly the velocity information at SINS position by the output speed information equivalence of log, in order to Complete compass alignment.Zhang Jun et al. is in " the moving base self-aligned technology of strapdown compass " (China's inertial technology journal, 2009) Propose a kind of strapdown compass punctual inertial sensor output calibration method, the method can will be produced because of carrier movement Gyro and accelerometer output signal filter, complete the compass autoregistration under moving base.But to gyro signal and acceleration Output signal gives timing, the most directly have employed the velocity information that log provides.And in real work, based on sensor The operation principle of self and the requirement of ship attitude measurement, log is generally mounted to boat bottom, and SINS is installed on , there is mounting distance between the two, i.e. there is outer lever arm effect in ship center of gravity.Outer lever arm effect will make log be inertial navigation There is error in the velocity information that system provides, and then compass alignment is produced impact.Therefore, there is the dynamic of outer lever arm effect in research Pedestal inertial navigation compass alignment methods has important practical significance.

(3) summary of the invention

It is an object of the invention to provide a kind of marine strapdown inertial navigation system moving base compass pair considering outer lever arm effect Quasi-method.

The technical solution used in the present invention comprises the following steps:

Step 1, by means of Ship Structure Graphing, measure following distance in advance: one is Δ y^b, represent that IMU installs center and meter Along the distance of carrier system (b system) y-axis between gift of money for a friend going on a journey installation center；Two is Δ z^bRepresent that IMU installs in center and log installation Along the mounting distance of carrier system z-axis between the heart；Three is Δ x^b, represent that IMU installs between center and log installation center along carrying The mounting distance of system x-axis；Four is L₁, represent that IMU installs the mounting distance between center and hull center of gravity along carrier system z-axis；

When step 2, ship navigation, SINS enters moving base compass initial alignment work state, and log enters Entering duty, output is along the velocity information of carrier system in real time

Step 3, SINS enter in moving base compass initial alignment process, in real time the output pitching α on naval vessel, horizontal stroke Shake β and course γ information and pitchrateRollrateAnd turning angle speedCarrier is also had to be tied to ground The strapdown attitude matrix of reason system

Step 4, the pitchrate obtained by step 3RollrateAnd turning angle speedAnd step Rapid 1 mounting distance obtained, measures the deviation δ v that tests the speed accordingly in the case of obtaining pitching, rolling, turning_α、δv_β、δv_γ, and will survey Speed deviation superposition obtains total range rate error δ v^b；

${\mathrm{\δv}}^b=\left[\begin{array}{c}{\mathrm{\δv}}_{\mathrm{\α}}\\ {\mathrm{\δv}}_{\mathrm{\β}}\\ {\mathrm{\δv}}_{\mathrm{\γ}}\end{array}\right]$

Step 5, utilize the strapdown attitude matrix that step 3 obtainsBy total range rate error δ v^bBe converted into along Department of Geography is total Velocity error:

${\mathrm{\δv}}^n=C_b^n{\mathrm{\δv}}^b$

Step 6, utilize the strapdown attitude matrix that step 3 obtainsLog is provided in real timeIt is transformed into along geographical The speed of system

Log output speed is corrected by step 7, the velocity deviation utilizing step 5 to obtain, and obtains along Department of Geography Speed after correction

$v_{dvl\_corrected}^n=v_{dvl}^n-{\mathrm{\δv}}^n$

Step 8, generalIntroduce moving base compass in quasi loop, it is achieved SINS moving base compass returns Road is initially directed at.

Beneficial effects of the present invention is verified by Matlab l-G simulation test:

Matlab simulated conditions:

Initial position chooses latitudeLongitude λ=126.6705 °；Inertial navigation three axle gyroscope constant value drift It is 0.01 °/h；Three axis accelerometer zero is 10 partially^-4m/s²；Gravity acceleration g=9.78049；The alignment parameter of compass alignment For: k₁=k₂=0.0113, k_E=k_N=9.81 × 10^-6, k_U=4.1 × 10^-6；Ship running speed is 3m/s；Boats and ships pitching width Spend 6 °, roll amplitude 3 °, turning amplitude 45 ° (pitching, rolling and turning are sinusoidal form, the cycle be respectively 8s, 15s, 90s)；Mounting distance between inertial navigation equipment and log: L₁=1m, Δ x^s=0.2m, Δ z^b=3m, Δ_y ^s=25m；During emulation Between be 3h.

Simulation results: Fig. 7 and Fig. 8 is the output speed and attitude not compensated, after Fig. 9 and Figure 10 is compensation Output speed and attitude.It can be seen that boats and ships are after driving stability from Fig. 7～10, by the compensation of external lever arm effect, defeated Go out speed and attitude numerical value has reduced, it was demonstrated that the feasibility of this invention.

(4) accompanying drawing explanation

The flow chart of Fig. 1 present invention.

Fig. 2 hull pitching schematic diagram.

Fig. 3 hull rolling schematic diagram.

Fig. 4 coordinate relation schematic diagram.

Fig. 5 hull turning schematic diagram.

Fig. 6 inertial navigation compass alignment method schematic diagram.

The output speed that Fig. 7 does not compensates.

The output attitude that Fig. 8 does not compensates.

Output speed after Fig. 9 compensation.

Output attitude after Figure 10 compensation.

(5) detailed description of the invention

The present invention is described in further detail below in conjunction with the accompanying drawings.

What the present invention proposed is a kind of inertial navigation moving base compass alignment methods peculiar to vessel considering outer lever arm effect, flow process Figure such as accompanying drawing 1, schematic diagram as shown in Figure 6, B^pFor harmful acceleration, f^bFor the acceleration under carrier coordinate system,For carrier Coordinate system (b system) arrives the transition matrix of geographic coordinate system (p system),The transition matrix of carrier coordinate system it is tied to for geographical coordinate,For correction angle speed calculated under geographic coordinate system,For gyro output carrier system under angular velocity information,ForAntisymmetric matrix,For carrier relative to the throwing under carrier coordinate system of the angular velocity of inertial coodinate system (i system) Shadow,For the earth from rotational acceleration projection under geographic coordinate system,For carrier relative to the angular velocity of the earth at geography Projection under Xi.

Moving base compass during carrier navigates by water is directed at needs to compensate three parts: spin velocityMotion angle SpeedHarmful acceleration B^p.The computational methods of three following (wherein Ω is the spin velocity of the earth, and R is earth radius,For carrier place latitude):

$B^p=({\mathrm{\ω}}_{ep}^p+2{\mathrm{\ω}}_{ie}^p)\×v^p$

If wanting three in compensation calculation above formula, needing log to provide velocity information, beyond institute, lever arm effect causes Log measured deviation will affect moving base compass alignment.

Hull direct route and turning are respectively such as accompanying drawing 2, accompanying drawing 3 and accompanying drawing 5, carrier coordinate system and orientation tracking coordinate system relation Scheming such as accompanying drawing 4, the method key step is as follows:

Step 1, by means of Ship Structure Graphing, measure following distance in advance: one is Δ y^b, represent that IMU installs center and meter Along the distance of carrier system (b system) y-axis between gift of money for a friend going on a journey installation center；Two is Δ z^bRepresent that IMU installs in center and log installation Along the mounting distance of carrier system z-axis between the heart；Three is Δ x^b, represent that IMU installs between center and log installation center along carrying The mounting distance of system x-axis；Four is L₁, represent that IMU installs the mounting distance between center and hull center of gravity along carrier system z-axis；

When step 2, ship navigation, SINS enters moving base compass initial alignment work state, and log enters Entering duty, output is along the velocity information of carrier system in real time

Step 3, SINS enter in moving base compass initial alignment process, in real time the output pitching α on naval vessel, horizontal stroke Shake β and course γ information and pitchrateRollrateAnd turning angle speedCarrier is also had to be tied to ground The strapdown attitude matrix of reason system

In compass loop is initially directed at, exports attitude information always, but the information of attitude matrix is also in the middle of alignment procedures It it not entirely accurate.The attitude matrix that carrier coordinate system thinks that geographic coordinate system is changed can be obtained in real time by attitude information Expression formula is as follows:

$C_b^n=\left[\begin{array}{ccc}\cos \mathrm{\β}\cos \mathrm{\γ}-\sin \mathrm{\α}\sin \mathrm{\β}\sin \mathrm{\γ}& \cos \mathrm{\β}\sin \mathrm{\γ}+\sin \mathrm{\α}\sin \mathrm{\β}\cos \mathrm{\γ}& -\cos \mathrm{\α}\sin \mathrm{\β}\\ -\cos \mathrm{\α}\sin \mathrm{\γ}& \cos \mathrm{\α}\cos \mathrm{\γ}& \sin \mathrm{\α}\\ \sin \mathrm{\β}\cos \mathrm{\γ}+\sin \mathrm{\α}\cos \mathrm{\β}\sin \mathrm{\γ}& \sin \mathrm{\β}\sin \mathrm{\γ}-\sin \mathrm{\α}\cos \mathrm{\β}\cos \mathrm{\γ}& \cos \mathrm{\α}\cos \mathrm{\β}\end{array}\right]$

PitchrateRollrateAnd turning angle speedCan be solved by following formula:

$\left[\begin{array}{c}{\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\α}}\\ {\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\β}}\\ {\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\γ}}\end{array}\right]=\frac{1}{\cos \mathrm{\α}}\left[\begin{array}{ccc}\cos \mathrm{\α}\cos \mathrm{\β}& 0& \cos \mathrm{\α}sin\mathrm{\β}\\ \sin \mathrm{\α}\sin \mathrm{\β}& \cos \mathrm{\α}& -sin\mathrm{\α}\cos \mathrm{\β}\\ -\sin \mathrm{\β}& 0& -\cos \mathrm{\β}\end{array}\right]\left[\begin{array}{c}{\mathrm{\ω}}_{nbx}^b\\ {\mathrm{\ω}}_{nby}^b\\ {\mathrm{\ω}}_{nbz}^b\end{array}\right]$

Wherein R is earth radius,For local latitude, ω_ieFor rotational-angular velocity of the earth, v_E、v_NIt is respectively east orientation and north orientation Speed

Step 4, the pitchrate obtained by step 3RollrateAnd turning angle speedAnd step Rapid 1 mounting distance obtained, measures the deviation δ v that tests the speed accordingly in the case of obtaining pitching, rolling, turning_α、δv_β、δv_γ, and will survey Speed deviation superposition obtains total range rate error δ v^b；

1. boats and ships are at the uniform velocity sailed through to, and bow stern speed is v_DIf now there is pitching, the angular speed of pitching isThe most now Range rate error is

${\mathrm{\δv}}_{\mathrm{\α}}=v_D^b-v_{\mathrm{\α}IMU}^b={\left[\begin{array}{ccc}0& {\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\α}}{\mathrm{\Δz}}^b& {\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\α}}{\mathrm{\Δy}}^b\end{array}\right]}^T$

As shown in Figure 2, pitching center O point on the extended line of hull center of gravity, v_αIMUSpeed for the position of centre of gravity of IMU Degree, Δ y^bRepresent the mounting distance along carrier system (b system) y-axis, Δ z between IMU and log^bRepresent edge between IMU and log The mounting distance of carrier system (b system) z-axis.

2. boats and ships are at the uniform velocity sailed through to, and bow stern speed is v_DIf now there is rolling, the angular speed of rolling isThe most now Range rate error is

${\mathrm{\δv}}_{\mathrm{\β}}=v_D^b-v_{\mathrm{\β}IMU}^b={\left[\begin{array}{ccc}-{\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\β}}{L}_1& 0& -{\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\β}}{\mathrm{\Δx}}^b\end{array}\right]}^T$

During as it is shown on figure 3, boats and ships produce rolling, rolling center O point is hull center of gravity, Δ x^bRepresent IMU and log it Between along the mounting distance of carrier system (b system) x-axis, L₁For between IMU and hull center of gravity along the mounting distance of carrier system z-axis.

3. assuming that boats and ships ignore the impact of pitching, the speed of hull and turning angle when turning motion will be in local level In face, therefore alignment error and the kinematic parameter of hull are projected to resolve in orientation tracking coordinate system (s system) by we.

Orientation tracking coordinate system (s system) is expressed as: the local horizontal coordinates that y-axis rotates with course, z-axis and geographical coordinate The z-axis of system overlaps, as shown in Figure 4:

Transition matrix between carrier system (b system) and orientation tracking coordinate system (s system) is

$C_s^b=\left[\begin{array}{ccc}\cos \mathrm{\β}& \sin \mathrm{\β}\sin \mathrm{\α}& -\sin \mathrm{\β}\cos \mathrm{\α}\\ 0& \cos \mathrm{\α}& sin\mathrm{\α}\\ \sin \mathrm{\β}& -\cos \mathrm{\β}\sin \mathrm{\α}& \cos \mathrm{\β}\cos \mathrm{\α}\end{array}\right]$

Ship's navigation bow stern speed is still v_DIf now occurring turning, the angular speed of turning isTesting the speed the most now misses Difference is

${\mathrm{\δv}}_{\mathrm{\γ}}=v_D^b-v_{\mathrm{\γ}IMU}^b=C_s^b\·{\left[\begin{array}{ccc}-{\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\γ}}{\mathrm{\Δy}}^s& {\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\γ}}{\mathrm{\Δx}}^s& 0\end{array}\right]}^T$

Δ x in formula^sRepresent the mounting distance along orientation tracking coordinate system (s system) x-axis, Δ y between IMU and log^sRepresent Along the mounting distance of orientation tracking coordinate system (s system) y-axis between IMU and log.

Comprehensive the most 1., 2., 3., obtain total range rate error:

${\mathrm{\δv}}^b=\left[\begin{array}{c}{\mathrm{\δv}}_x\\ {\mathrm{\δv}}_y\\ {\mathrm{\δv}}_z\end{array}\right]={\mathrm{\δv}}_{\mathrm{\α}}+{\mathrm{\δv}}_{\mathrm{\β}}+{\mathrm{\δv}}_{\mathrm{\γ}}$

Step 5, utilize the strapdown attitude matrix that step 3 obtainsBy total range rate error δ v^bBe converted into along Department of Geography is total Velocity error:

${\mathrm{\δv}}^n=C_b^n{\mathrm{\δv}}^b$

Step 6, utilize the strapdown attitude matrix that step 3 obtainsLog is provided in real timeIt is transformed into along geographical The speed of system

Log output speed is corrected by step 7, the velocity deviation utilizing step 5 to obtain, and obtains along Department of Geography Speed after correction

$v_{dvl\_corrected}^n=v_{dvl}^n-{\mathrm{\δv}}^n$

Step 8, generalIntroduce moving base compass in quasi loop, it is achieved SINS moving base compass returns Road is initially directed at.

Claims (4)

1. consider the moving base SINS compass alignment methods of outer lever arm effect, it is characterized in that by means of Ship Structure Figure, measures in inertial measurement cluster (Inertial Navigation Unit, IMU) in SINS, log installation Mounting distance between the heart, naval vessel center of gravity, and combine SINS self output measurement and obtain log and test the speed deviation, SINS moving base compass alignment procedures is corrected for.

The moving base SINS compass alignment methods of the outer lever arm effect of consideration the most according to claim 1, it is special Levy is to comprise the following specific steps that:

Step 1, by means of Ship Structure Graphing, measure following distance in advance: one is Δ y^b, represent that IMU installs center and log peace Along the distance of carrier system (b system) y-axis between dress center；Two is Δ z^b, represent that IMU installs between center and log installation center Mounting distance along carrier system z-axis；Three is Δ x^b, represent that IMU installs between center and log installation center along carrier system x-axis Mounting distance；Four is L₁, represent that IMU installs the mounting distance between center and hull center of gravity along carrier system z-axis；

When step 2, ship navigation, SINS enters moving base compass initial alignment work state, and log is just entering Often duty, output is along the velocity information of carrier system in real time

Step 3, SINS enter in moving base compass initial alignment process, in real time the output pitching α on naval vessel, rolling β With course γ information and pitchrateRollrateAnd turning angle speedCarrier is also had to be tied to geography The strapdown attitude matrix of system

Step 4, the pitchrate obtained by step 3RollrateAnd turning angle speedAnd step 1 The mounting distance arrived, measures the deviation δ v that tests the speed obtaining being introduced by naval vessel pitching, rolling, turning_α、δv_β、δv_γ, and will test the speed partially Difference superposition obtains total range rate error δ v^b；

${\mathrm{\δv}}^b=\left[\begin{array}{c}{\mathrm{\δv}}_{\mathrm{\α}}\\ {\mathrm{\δv}}_{\mathrm{\β}}\\ {\mathrm{\δv}}_{\mathrm{\γ}}\end{array}\right]$

Step 5, utilize the strapdown attitude matrix that step 3 obtainsBy total range rate error δ v^bIt is converted into the general speed along Department of Geography Error:

${\mathrm{\δv}}^n=C_b^n{\mathrm{\δv}}^b$

Step 6, utilize the strapdown attitude matrix that step 3 obtainsLog is provided in real timeIt is transformed into along Department of Geography Speed

Log output speed is corrected by step 7, the velocity deviation utilizing step 5 to obtain, and obtains correcting along Department of Geography After speed

$v_{dvl\_corrected}^n=v_{dvl}^n-{\mathrm{\δv}}^n$

Step 8, generalIntroduce moving base compass in quasi loop, it is achieved at the beginning of SINS moving base compass loop Begin alignment.

The moving base SINS compass alignment methods of the outer lever arm effect of consideration the most according to claim 2, it is special Levy is that pitching described in step 4 introduces the deviation that tests the speed and is:

${\mathrm{\δv}}_{\mathrm{\α}}={\left[\begin{array}{ccc}0& {\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\α}}{\mathrm{\Δz}}^b& {\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\α}}{\mathrm{\Δy}}^b\end{array}\right]}^T$

Rolling introduces the deviation that tests the speed:

${\mathrm{\δv}}_{\mathrm{\β}}={\left[\begin{array}{ccc}-{\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\β}}{L}_1& 0& -{\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\β}}{\mathrm{\Δx}}^b\end{array}\right]}^T$

The deviation that tests the speed that course change introduces is:

${\mathrm{\δv}}_{\mathrm{\γ}}=C_s^b\·{\left[\begin{array}{ccc}-{\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\γ}}{\mathrm{\Δy}}^s& {\stackrel{\·}{\mathrm{\ψ}}}_{\mathrm{\γ}}{\mathrm{\Δx}}^s& 0\end{array}\right]}^T$

The moving base SINS compass alignment methods of the outer lever arm effect of consideration the most according to claim 3, it is special Levy is that the transition matrix between orientation tracking coordinate system (s system) and carrier system (b system) is

$C_s^b=\left[\begin{array}{ccc}cos\mathrm{\β}& sin\mathrm{\β}sin\mathrm{\α}& -\sin \mathrm{\β}cos\mathrm{\α}\\ 0& cos\mathrm{\α}& sin\mathrm{\α}\\ sin\mathrm{\β}& -cos\mathrm{\β}sin\mathrm{\α}& \cos \mathrm{\β}cos\mathrm{\α}\end{array}\right]$

This matrix can be exported the pitching α on naval vessel in real time by step 3 SINS, rolling β obtains.