CN103047999B - Gyro error method for quick estimating in a kind of ship-borne master/sub inertial navigation Transfer Alignment process - Google Patents

Abstract

Gyro error method for quick estimating in a kind of ship-borne master/sub inertial navigation Transfer Alignment process, for the Transfer Alignment in naval vessel master/sub-portfolio, devise a kind of gyro error method for quick estimating be applicable under mooring/at the uniform velocity direct route condition, antithetical phrase inertial navigation gyroscope constant value error is estimated fast, under the support of real-time multi-task operating system, sub-inertial navigation system carries out circular navigation to same group of data and resolves and information fusion, make full use of the high speed performance of computing machine, in Transfer Alignment process, complete the estimation to gyroscope constant value error fast.The present invention does not change the existing algorithm of navigation calculation, does not change the filter construction in Transfer Alignment information fusion algorithm and information matches mode, makes full use of existing navigational computer abundant resources, accelerates the estimating speed to gyro error in Transfer Alignment process.

Description

Gyro error method for quick estimating in a kind of ship-borne master/sub inertial navigation Transfer Alignment process

Technical field

The present invention relates to ship-borne master/sub inertial navigation fast transfer alignment method, under being specially adapted to naval vessel mooring or at the uniform velocity direct route condition, the quick estimation of gyro error is the gyro error method for quick estimating in a kind of ship-borne master/sub inertial navigation Transfer Alignment process.

Background technology

Under carrier-borne environment, the precision of main inertial navigation (hip-based platform formula inertial navigation system) is generally higher than the several magnitude of precision of sub-inertial navigation (as ship-based missile strap-down inertial navigation system).Sub-inertial navigation utilizes that the navigation information of main inertial navigation completes initialization, misalignment is estimated, the process of device estimation of error is called Transfer Alignment.

Transfer Alignment as the technology that is a kind of general, general character of field of inertia technology, to be widely used on the weapon platforms such as battlebus, opportunity of combat, naval vessel, spacecraft carry the initial alignment of sub-inertial navigation system.Based on the requirement of armament systems rapid-action, the rapidity of Transfer Alignment is the target of initial alignment always.1989, Kain and Cloutier proposes first " speed+attitude " matching way, and coordinate and shake wing action with carrier aircraft, the alignment precision of 1mrad can be reached in 10s.In addition, the people such as Spalding, Shortelle and Graham also demonstrates the validity of said method.

Said method, when highlighting misalignment estimation rapidity in alignment procedures, weakens or have ignored the estimation to device error.But inertia device exists following problem: 1) after long storage time, can there is the drift of certain magnitude, device precision is lower, drifts about more serious; 2) existence successively starts error, and device precision is lower, and error is larger.For in low precision sub-inertial navigation system for, when its initial alignment, if do not estimate device error, device error will be caused in long-time navigation calculation process to be integrated amplification, thus reduce system navigate precision.

In fact, in Transfer Alignment Kalman filter, the observability of each quantity of state depends on information matches mode and carrier maneuver mode.When oscillating motion, adopt " speed+attitude " matching way, the estimation of site error needs several minutes, is unable to estimate in 10s.

Summary of the invention

The problem to be solved in the present invention is: under carrier-borne environment, and existing Transfer Alignment have ignored the estimation of error to inertia device, reduces navigation accuracy, and prior art is quick not to the estimation of error, the real-time of impact navigation.

Technical scheme of the present invention is: the gyro error method for quick estimating in a kind of ship-borne master/sub inertial navigation Transfer Alignment process, under the support of real-time multi-task operating system, gyroscope constant value error is estimated fast, in master/sub-inertial navigation Transfer Alignment process, navigation calculation is carried out in sub-inertial navigation, sub-inertial navigation utilizes the navigation data of main inertial navigation to carry out information fusion, if t ₀for the initial time of gyroscope constant value estimation of error, be also the initial time of initial alignment, t ₀~ t ₁for data acquisition, data storage, real-time navigation resolve and information fusion and attitude matrix update time section, t ₁~ t ₂for based on t ₀~ t ₁between store information circular navigation resolve and information fusion and attitude matrix update time section, the determination of above-mentioned each time is as follows:

T1) for concrete sub-inertial navigation system, leading/sub-inertial navigation Transfer Alignment in, the time required for whole aligning has been determined by sub-inertial navigation gyro error convergence curve, again according to sub-inertial navigation measurement and navigation calculation update cycle Δ t, determine the total update times of navigation calculation required for whole aligning, be set as k _sum; According to main inertial navigation navigation information updating cycle Δ T, determined the information fusion number of times required for whole aligning, Δ T is the information fusion cycle; Under the working environment determined, navigation calculation and information fusion sequential relationship are determined, after navigation calculation number of times is determined, information fusion number of times can be determined;

T2) according to sub-inertial navigation instrumented data quality, main inertial navigation measurement information quality, setting moment t ₁and time period t ₀~ t ₁, and calculate navigation calculation update times in this time period according to Δ t, be set as k _sum1;

T3) from the total update times k of navigation calculation required for whole aligning _sumin, deduction step T2) middle t ₀~ t ₁navigation calculation update times k in time period _sum1, obtained the navigation calculation update times that whole aligning has also needed, be set as k _sum2, k _sum2=k _sum-k _sum1, thus obtain t ₁~ t ₂the circular navigation of time period resolves cycle index, is set as m, m=k _sum2/ k _sum1, when m is not integer, by m value upwards rounding, and according to the m value adjustment k after rounding _sum2; Moment t ₂the performance being resolved cycle index m and navigational computer by circular navigation is determined jointly, and when m determines, navigational computer dominant frequency is higher, t ₂with t ₁between difference less;

According to the described time determined, in Transfer Alignment, complete sub-inertial navigation gyroscope error estimation, comprise the steps:

1) at t ₀in the moment, utilize the position of main inertial navigation, speed carries out initialization to the corresponding navigation information of attitude information antithetical phrase inertial navigation, obtain the position of sub-inertial navigation, speed and attitude matrix t is time variable; Flash setting t ₀the carrier coordinate system in moment is b ₀, obtain i is (3 × 3) unit matrix;

2) in time period t ₀~ t ₁in, sub-inertial navigation carries out the collection of inertia type instrument data, storage, navigation calculation by cycle Δ t, and utilizes formula (6) to upgrade sub-inertial navigation carrier coordinate system b relative to b ₀the attitude matrix of system

$C_{{b,k}_1}^{b_0}=C_{{b,k}_1-1}^{b_0}(I+\mathrm{\Δt}{\mathrm{\ω}}_{{\mathrm{ib},k}_1}^b\×)---\left(6\right)$

In formula, subscript k ₁=1 ~ k _sum1represent the number of times label that navigation calculation upgrades, for the data of sub-inertial navigation gyro Real-time Collection, $C_{b,0}^{b_0}=C_b^{b_0}\left(t_0\right)=I;$

Sub-inertial navigation simultaneously receives the navigation information of autonomous inertial navigation according to cycle Δ T and stores, and described navigation information comprises speed and course, and records the sequential relationship between main inertial navigation navigation information and sub-inertial navigation instrumented data; Main and sub inertial navigation Transfer Alignment is carried out by information fusion;

3) in step 2) terminate t ₁in the moment, obtain the real-time carrier matrix in this moment the carrier coordinate system in this moment of flash setting is b ₁, have

4) in time period t ₁~ t ₂in, sub-inertial navigation system works as follows:

41) to step 2) in the sub-inertial navigation inertia type instrument data that gather carry out m circular navigation and resolve and information fusion, t ₁~ t ₂inside carry out m circular navigation to resolve, each subcycle cycle is: t ₁₀~ t ₁₁, t ₂₀~ t ₂₁..., t _j0~ t _j1... t _m0~ t _m1, j=1 ~ m represents the label in subcycle cycle, in the navigation calculation and information fusion process of each subcycle, and sub-inertial navigation instrumented data used and main inertial navigation information corresponding t respectively ₀~ t ₁the navigation information of the instrumented data that interior sub-inertial navigation system gathers and main inertial navigation, within each subcycle cycle, navigation calculation update times and information fusion number of times and t ₀~ t ₁interior number of times is equal respectively; In circulation solution process, naval vessel is in mooring or at the uniform velocity sails through to state, the speed of start time is resolved in each subcycle, a subcycle end cycle moment is directly got in position speed and position, but because boats and ships exist oscillating motion, the attitude that start time is resolved in each subcycle needs following process, at each subcycle t _j0~ t _j1start time t _j0initial attitude matrix:

$C_b^n\left(t_{j0}\right)=C_b^n\left(t_{(j-1)1}\right){\left(C_b^{b_0}\left(t_1\right)\right)}^T---\left(7\right)$

In formula, for at t _{(j-1) 1}the attitude matrix of the carrier coordinate system b Relative Navigation coordinate system n that the moment calculates, the i.e. sub attitude matrix at the end of resolving that circulates of jth-1, $C_b^{b_0}\left(t_1\right)=C_{{b,k}_{\mathrm{sum}1}}^{b_0},$ $C_b^n\left(t_{10}\right)=C_b^n\left(t_1\right){\left(C_b^{b_0}\left(t_1\right)\right)}^T;$

In each subcycle process, by step 2) in record sequential relationship carry out navigation calculation and information fusion;

42) carry out above-mentioned circular navigation resolve with information fusion while, sub-inertial navigation carries out Real-time Collection to inertia type instrument data, upgrades and calculates present carrier coordinate system b system relative to b ₁the attitude matrix of system its discrete form is:

$C_{{b,k}_2}^{b_1}=C_{{b,k}_2-1}^{b_1}(I+\mathrm{\Δt}{\mathrm{\ω}}_{\mathrm{ib}{k}_2}^b\×)---\left(9\right)$

Wherein $C_{b,0}^{b_1}=C_b^{b_1}\left(t_1\right)=I,$ K ₂for update times, step 42) finally obtain

5) the circular navigation completing m cycle resolve and correspondence information fusion after, sub-inertial navigation system is according to t _m1moment carrier coordinate system b is relative to the Attitude estimation matrix of navigational coordinate system n i.e. t ₁the estimated value afterwards of moment attitude matrix, and t ₂moment, carrier coordinate system b was relative to b ₁real-time attitude matrix obtain t ₂the real-time attitude matrix in moment for the navigation of sub-inertial navigation; Sub-inertial navigation simultaneously obtains t _m1the gyroscope error estimation value in moment, i.e. t ₁the estimated value afterwards of moment gyro error, by t _m1the gyroscope error estimation value in moment is as final gyroscope error estimation value;

T4) repeatedly above-mentioned steps T2 is carried out) and step T3), by the form of off-line simulation, select different time point t ₁, obtain different circular navigation and resolve period m, according to step 1)-5) gyro error is estimated fast, selecting can close to T1) in the t of estimation effect ₁with m as optimum time point t ₁with circular navigation computation cycles number m, formally for the Transfer Alignment of ship-borne master/sub inertial navigation, described estimation effect refers to T1) the convergence effect of neutron inertial navigation gyro error convergence curve; Step 1)-5 is carried out in actual ship-borne master/sub inertial navigation Transfer Alignment process), realize gyro error and estimate fast.

Described real-time multi-task operating system is multiple task real-time operation system VxWorks, completes following four tasks, and the scheduling of task is automatically performed by the priority level of multiple task real-time operation system VxWorks according to task, four tasks below running in sub-inertial navigation:

1) task one: sub-inertial navigation instrumented data gathers, store and navigation calculation and more new Algorithm, priority level is the highest;

2) task two: sub-inertial navigation instrumented data gathers, more new Algorithm, priority level second;

3) task three: sub-inertial navigation carries out data acquisition, storage and information fusion to main inertial navigation, priority level the 3rd;

4) task four: sub-inertial navigation is resolved and information fusion based on the circular navigation storing data, and priority level is minimum.In Transfer Alignment process, the navigation computation of sub-inertial navigation is:

$C_{b,k}^n=C_{b,k-1}^n(I+\mathrm{\Δt}{\mathrm{\ω}}_{\mathrm{nb},k}^b\×)---\left(1\right)$

$V_k^n=V_{k-1}^n+\mathrm{\Δt}[C_{b,k-1}^n{f}_k^b-(2{\mathrm{\ω}}_{\mathrm{ie},k-1}^n+{\mathrm{\ω}}_{\mathrm{en},k-1}^n)\×V_{k-1}^n+g^n]---\left(2\right)$

$L_k=L_{k-1}+\frac{\mathrm{\Δt}{V}_{N,k-1}^n}{R_M+h_{k-1}},{\mathrm{\λ}}_k={\mathrm{\λ}}_{k-1}+\frac{\mathrm{\Δt}{V}_{E,k-1}^n\sec L_{k-1}}{R_N+h_{k-1}},h_k=h_{k-1}+\mathrm{\Δt}{V}_{U,k-1}^n---\left(3\right)$

In formula, for the attitude matrix of sub-inertial navigation carrier coordinate system b Relative Navigation coordinate system n, I is (3 × 3) unit matrix, and subscript k=1 ~+∞ represents the update times label of navigation calculation, and n represents navigational coordinate system, and b represents carrier coordinate system, and i represents inertial coordinates system, represent that terrestrial coordinate system e is relative to the projected angle speed of inertial coordinates system i in navigational coordinate system n, represent that navigational coordinate system n is relative to the projected angle speed of terrestrial coordinate system e in navigational coordinate system n; In formula (1) ${\mathrm{\ω}}_{\mathrm{nb}}^b={\mathrm{\ω}}_{\mathrm{ib}}^b-{\left(C_b^n\right)}^T({\mathrm{\ω}}_{\mathrm{ie}}^n+{\mathrm{\ω}}_{\mathrm{en}}^n),$ for sub-inertial navigation gyro image data, ${\mathrm{\ω}}_{\mathrm{en}}^n={\left[\begin{array}{ccc}-V_N^n/(R_M+h)& V_E^n/(R_N+h)& \left(V_E^n\tan L\right)/(R_N+h)\end{array}\right]}^T,$ $V^n=\left[\begin{array}{ccc}{V}_E^n& V_N^n& V_U^n\end{array}\right]$ Be respectively the east of sub-inertial navigation, north, sky to speed, L, λ and h represent speed, latitude, longitude and height under navigational coordinate system respectively, f ^bfor sub-inertial navigation accelerometer image data, g ⁿfor the projection of terrestrial gravitation acceleration in navigational coordinate system, R _mand R _nbe respectively meridian circle and the prime vertical radius of the navigation location earth; Operational symbol "×" represents vectorial backslash computing, under carrier-borne environment, directly get sub-inertial navigation sky to speed be highly zero.

In Transfer Alignment process, main and sub inertial navigation information is fused to:

Adopt Kalman filter as information fusion filtering device, get sub-inertial navigation east orientation/north orientation velocity error, misalignment and gyro error as system state vector, namely

X=[δV _EδV _Nφ _Eφ _Nφ _Uε _xε _yε _z] ^T

Wherein, δ V _e/ δ V _nfor east orientation/north orientation velocity error; φ _e, φ _n, φ _ube respectively pitching, rolling, course misalignment; ε _x, ε _y, ε _zbe respectively three axle gyro errors;

Get system state equation,

$\stackrel{\·}{X}\left(t\right)=A\left(t\right)X\left(t\right)+W\left(t\right)---\left(4\right)$

In formula, A (t) is state matrix, and W (t) is system noise, according to system state variables medium velocity, misalignment error equation, and gyro is from the projection relation of carrier coordinate system b navigation coordinate system n, state matrix A (t) is expressed as:

$A\left(t\right)=\left[\begin{array}{cccccccc}\frac{V_N}{R}\tan L& {2\mathrm{\ω}}_{\mathrm{ie}}\sin L+\frac{V_E}{R}\tan L& 0& {-f}_U& f_N& 0& 0& 0\\ -({2\mathrm{\ω}}_{\mathrm{ie}}\sin L+\frac{V_E}{R}\tan L)& 0& f_U& 0& {-f}_E& 0& 0& 0\\ 0& -\frac{1}{R}& 0& {\mathrm{\ω}}_{\mathrm{ie}}\sin L+\frac{V_E}{R}\tan L& -({\mathrm{\ω}}_{\mathrm{ie}}\cos L+\frac{V_E}{R})& -T_{11}& {-T}_{12}& {-T}_{13}\\ \frac{1}{R}& 0& -({\mathrm{\ω}}_{\mathrm{ie}}\sin L+\frac{V_E}{R}\tan L)& 0& -\frac{V_N}{R}& {-T}_{21}& -T_{22}& {-T}_{23}\\ \frac{1}{R}\tan L& 0& {\mathrm{\ω}}_{\mathrm{ie}}\cos L+\frac{V_E}{R}& \frac{V_N}{R}& 0& -T_{31}& {-T}_{32}& {-T}_{33}\\ 0& 0& 0& 0& 0& 0& 0& 0\\ 0& 0& 0& 0& 0& 0& 0& 0\\ 0& 0& 0& 0& 0& 0& 0& 0\end{array}\right]$

Wherein, V _e, V _nfor sub-inertial navigation east orientation and north orientation speed, ω _iefor rotational-angular velocity of the earth, R is earth radius, and L is local geographic latitude, f _e, f _n, f _ube respectively sub-inertial navigation acceleration measurement f ^bprojection in navigational coordinate system n, T _pq, p, q=1,2,3 is the attitude matrix of sub-inertial navigation carrier coordinate system b Relative Navigation coordinate system n each element;

" speed+course " the information matches mode of employing, get son, the speed of main inertial navigation, course difference directly construct measurement information, i.e. son/main inertial navigation navigational system measures vector and is

Z=[V _E-V _MEV _N-V _MNH-H _M] ^T

Wherein, V _ewith V _mEbe respectively the east orientation speed of son, main inertial navigation; V _nwith V _mNbe respectively the north orientation speed of son, main inertial navigation; H and H _mbe respectively the course information of son, main inertial navigation, H is from sub-inertial navigation attitude matrix middle extracting directly;

System measurements equation is

Z(t)=H(t)X(t)+V(t) （5）

In formula, H (t) is measurement matrix, and V (t) is measurement noise, according to measuring vector and the relation of state vector, has measurement matrix to be

$H=\left[\begin{array}{cccccc}1& 0& 0& 0& 0& \\ 0& 1& 0& 0& 0& 0_{3\×3}\\ 0& 0& -\frac{T_{12}{T}_{32}}{T_{12}^2+T_{22}^2}& -\frac{T_{22}{T}_{32}}{T_{12}^2+T_{22}^2}& -1& \end{array}\right]$

In information fusion process, adopt Closed-cycle correction mode, information fusion is estimated velocity error, misalignment and the gyroscope error estimation value obtained feeds back to sub-inertial navigation system and participate in navigation calculation.

For the Transfer Alignment in naval vessel master/sub-portfolio, the present invention devises a kind of gyro error method for quick estimating be applicable under mooring/at the uniform velocity direct route condition, antithetical phrase inertial navigation gyroscope constant value error is estimated fast, under the support of real-time multi-task operating system, sub-inertial navigation system carries out circular navigation to same group of data and resolves and information fusion, make full use of the high speed performance of computing machine, in Transfer Alignment process, complete the estimation to gyroscope constant value error fast.Method tool of the present invention has the following advantages: (1) does not change the information matches pattern of existing Transfer Alignment, does not require carrier to do specific motor-driven; (2) the Kalman filter technology of current comparative maturity is directly utilized to estimate; (3) the more than needed computer resource of navigational computer within posture renewal cycle and information fusion cycle is utilized to carry out work, requirements at the higher level are not proposed to computing power, although alignment speed still depends on computing power to a great extent, but when computer resource same with existing navigational system configures, Transfer Alignment speed faster can be obtained.

Accompanying drawing explanation

Fig. 1 is that the present invention is along time shaft alignment procedures step exploded view;

Fig. 2 is the information fusion algorithm schematic diagram that the present invention uses;

Fig. 3 is loop calculation figure of the present invention;

Fig. 4 is misalignment evaluated error figure under mooring condition of the present invention;

Fig. 5 is the estimation curve figure to site error under mooring condition of the present invention;

Fig. 6 is misalignment evaluated error figure under the present invention's at the uniform velocity direct route condition;

Fig. 7 is the estimation curve figure to gyro error under the present invention's at the uniform velocity direct route condition.

Embodiment

The present invention thinks after analysis strap-down inertial navigation system replaces the relevant feature of " physical platform " in gimbaled inertial navigation system with " mathematical platform ", in strap-down inertial navigation system, same data can be utilized to carry out navigation calculation, and constantly adjust mathematical platform, make full use of the high speed performance of computing machine, in Transfer Alignment process, complete the estimation to site error fast.

Below in conjunction with accompanying drawing, the invention process method is described in more detail:

In Fig. 1, t ₀for the initial time of gyroscope constant value estimation of error, t ₀~ t ₁for data store, navigation calculation and information fusion and update time section, t ₁~ t ₂for resolving with information fusion and based on gyro to measure information based on storing the circular navigation of information update time section.Δ t is inertia type instrument data and the navigation calculation update cycle of sub-inertial navigation; Δ T is main inertial navigation information update cycle and boss's inertial navigation information fusion cycle, and Δ T is the integral multiple of Δ t, and in the present invention, Δ t is the navigation calculation cycle, and Δ T is the information fusion cycle.For the master determined/sub-inertial navigation combined system, Δ t and Δ T is determined value, and sub-inertial navigation instrumented data and main inertial navigation are determined with reference to navigation information sequential relationship, also namely navigation calculation and information fusion sequential relationship are determined, after navigation calculation number of times is determined, information fusion number of times can be determined.Above-mentioned t ₁selection and cycle index m determination need determined by Multi simulation running according to concrete system.Specific as follows:

T1) for concrete sub-inertial navigation system, leading/sub-inertial navigation Transfer Alignment in, by observing the convergence situation of sub-inertial navigation gyroscope error estimation curve, determine the time required for whole aligning, measure and the navigation update cycle according to sub-inertial navigation, determined the total update times k of navigation calculation required for whole aligning _sum; According to the main inertial navigation navigation information updating cycle, determine the information fusion number of times required for whole aligning;

T2) according to sub-inertial navigation instrumented data quality, main inertial navigation measurement information quality, select time t ₁, and calculate navigation calculation update times in this time period according to Δ t, be set as k _sum1, t ₀~ t ₁the time period obtaining basic data in the present invention, t below ₁~ t ₂time period is according to t ₀~ t ₁the data that time period obtains carry out further estimation of error, t ₀~ t ₁length determine according to the quality of data of sub-inertial navigation, main inertial navigation as required;

T3) from the total update times k of navigation calculation required for whole aligning _sumin, deduction step T2) middle t ₀~ t ₁navigation calculation update times k in time period _sum1, obtained the navigation calculation update times that whole aligning has also needed, be set as k _sum2=k _sum-k _sum1, thus obtain t ₁~ t ₂the circular navigation of time period resolves cycle index, is set as m=k _sum2/ k _sum1, when m is not positive number, by m value upwards rounding, and according to the m value adjustment k after rounding _sum2.Time t ₂the performance being resolved cycle index and navigational computer by circular navigation is determined jointly, and when m determines, computer main frequency is higher, t ₂with t ₁between difference less;

T4) according to above-mentioned steps T2) and step T3), by the form of off-line simulation, alternative optimum time point t ₁with circular navigation computation cycles number m, be actually used in the Transfer Alignment of master/sub-inertial navigation, described the best refers to according to selected time point t ₁with the convergence situation of the most closing to reality inertial navigation gyroscope error estimation curve of gyroscope error estimation that period m obtains.

The present invention carries out gyroscope error estimation under the support of real-time multi-task operating system:

In Fig. 1, (a) is at t ₀~ t ₁time period, because information fusion calculation amount is relatively large, the some Δ t of general needs can complete, according to single task program schema, namely just can carry out instrumented data collection and navigation calculation after completing information fusion, then program design is complicated, is difficult to meet navigation calculation requirement of real-time; B () is at t ₁~ t ₂time period, based on the t stored ₀~ t ₁the data of time period carry out navigation calculation and information fusion, need to take to remove all computer resources outside renewal, according to single task pattern, then program design is complicated, is difficult to meet navigation calculation requirement of real-time.

Can not above-mentioned requirements be met based on single task pattern, introduce real-time multi-task operating system VxWorks, under VxWorks environment, be defined as follows task:

1) task one: instrumented data collection, store and navigation calculation and more new Algorithm, priority level is the highest;

2) task two: instrumented data collection, more new Algorithm, priority level second;

3) task three: main inertial guidance data collection, storage and information fusion, priority level the 3rd;

4) task four: resolve and information fusion based on the circular navigation storing data, priority level is minimum.

Above-mentioned task one, three is initiated after initialization, takies navigational computer resource according to the priority level of task, and when not carrying out information fusion, task one takies separately navigational computer resource; When carrying out information fusion, if desired carry out instrumented data collection, storage and navigation calculation, then task three abandons taking navigational computer resource, and task one takies, and after task one completes, task three is resumed.

At t ₁in the moment, after task one completes, task one is deleted, and task two is initiated simultaneously; After task three completes, task three is also deleted, and task four is initiated simultaneously; At t ₁~ t ₂time period, task two and task four take navigational computer resource according to priority level, and when task two does not need to perform, task four takies navigational computer resource and carries out circular navigation and resolve.

Navigation calculation of the present invention is specially:

$C_{b,k}^n=C_{b,k-1}^n(I+\mathrm{\Δt}{\mathrm{\ω}}_{\mathrm{nb},k}^b\×)---\left(1\right)$

$V_k^n=V_{k-1}^n+\mathrm{\Δt}[C_{b,k-1}^n{f}_k^b-({2\mathrm{\ω}}_{\mathrm{ie},k-1}^n+{\mathrm{\ω}}_{\mathrm{en},k-1}^n)\×V_{k-1}^n+g^n]---\left(2\right)$

$L_k=L_{k-1}+\frac{\mathrm{\Δt}{V}_{N,k-1}^n}{R_M+h_{k-1}},$ ${\mathrm{\λ}}_k={\mathrm{\λ}}_{k-1}+\frac{\mathrm{\Δt}{V}_{E,k-1}^n\sec L_{k-1}}{R_N+h_{k-1}},$ $h_k=h_{k-1}+\mathrm{\Δt}{V}_{U,k-1}^n---\left(3\right)$

In formula, for the attitude matrix of sub-inertial navigation carrier coordinate system b Relative Navigation coordinate system n, I is (3 × 3) unit matrix, and subscript k=1 ~+∞ represents the update times label of navigation calculation, and n represents navigational coordinate system, and b represents carrier coordinate system, and i represents inertial coordinates system, represent that terrestrial coordinate system e is relative to the projected angle speed of inertial coordinates system i in navigational coordinate system n, represent that navigational coordinate system n is relative to the projected angle speed of terrestrial coordinate system e in navigational coordinate system n.In formula (4) ${\mathrm{\ω}}_{\mathrm{nb}}^b={\mathrm{\ω}}_{\mathrm{ib}}^b-{\left(C_b^n\right)}^T({\mathrm{\ω}}_{\mathrm{ie}}^n+{\mathrm{\ω}}_{\mathrm{en}}^n),$ for sub-inertial navigation gyro image data, ${\mathrm{\ω}}_{\mathrm{en}}^n={\left[\begin{array}{ccc}-V_N^n/(R_M+h)& V_E^n/(R_N+h)& \left(V_E^n\tan L\right)/(R_N+h)\end{array}\right]}^T,$ $V^n=\left[\begin{array}{ccc}{V}_E^n& V_N^n& V_U^n\end{array}\right]$ Be respectively the east of sub-inertial navigation, north, sky to speed, L, λ and h represent speed, latitude, longitude and height under navigational coordinate system respectively, f ^bfor sub-inertial navigation accelerometer image data, g ⁿfor the projection of terrestrial gravitation acceleration in navigational coordinate system, R _mand R _nbe respectively meridian circle and the prime vertical radius of the navigation location earth; Operational symbol "×" represents vectorial backslash computing, under carrier-borne environment, directly get sub-inertial navigation sky to speed be highly zero.Information fusion of the present invention specifically adopts the matching way in Kalman filter and " speed+course ", as shown in Figure 2.

Get east orientation/north orientation velocity error, misalignment and gyro error as system state vector, namely

X=[δV _EδV _Nφ _Eφ _Nφ _Uε _xε _yε _z] ^T

Wherein, δ V _e/ δ V _nfor east orientation/north orientation velocity error; φ _e~Ufor pitching, rolling, course misalignment; ε _x~zbe three axle gyro errors.

Get system state equation,

$\stackrel{\·}{X}\left(t\right)=A\left(t\right)X\left(t\right)+W\left(t\right)---\left(4\right)$

In formula, A (t) is state matrix, and W (t) is system noise, according to system state variables medium velocity, misalignment error equation, and gyro is from carrier coordinate system b navigation coordinate system n projection relation, state matrix A (t) is expressed as:

$A\left(t\right)=\left[\begin{array}{cccccccc}\frac{V_N}{R}\tan L& {2\mathrm{\ω}}_{\mathrm{ie}}\sin L+\frac{V_E}{R}\tan L& 0& {-f}_U& f_N& 0& 0& 0\\ -({2\mathrm{\ω}}_{\mathrm{ie}}\sin L+\frac{V_E}{R}\tan L)& 0& f_U& 0& {-f}_E& 0& 0& 0\\ 0& -\frac{1}{R}& 0& {\mathrm{\ω}}_{\mathrm{ie}}\sin L+\frac{V_E}{R}\tan L& -({\mathrm{\ω}}_{\mathrm{ie}}\cos L+\frac{V_E}{R})& -T_{11}& {-T}_{12}& {-T}_{13}\\ \frac{1}{R}& 0& -({\mathrm{\ω}}_{\mathrm{ie}}\sin L+\frac{V_E}{R}\tan L)& 0& -\frac{V_N}{R}& {-T}_{21}& -T_{22}& {-T}_{23}\\ \frac{1}{R}\tan L& 0& {\mathrm{\ω}}_{\mathrm{ie}}\cos L+\frac{V_E}{R}& \frac{V_N}{R}& 0& -T_{31}& {-T}_{32}& {-T}_{33}\\ 0& 0& 0& 0& 0& 0& 0& 0\\ 0& 0& 0& 0& 0& 0& 0& 0\\ 0& 0& 0& 0& 0& 0& 0& 0\end{array}\right]$

Wherein, V _e, V _nfor east orientation and north orientation speed, ω _iefor rotational-angular velocity of the earth, R is earth radius, and L is local geographic latitude, f _e, f _n, f _ube respectively acceleration measurement f ^bprojection in navigational coordinate system n, T _ij(i, j=1,2,3) are the attitude matrix of sub-inertial navigation carrier coordinate system b Relative Navigation coordinate system n each element;

Employing speed+course information matching way.

Get son, the speed of main inertial navigation, course difference directly construct measurement information, namely system measurements vector is

Z=[V _E-V _MEV _N-V _MNH-H _M] ^T

Wherein, V _ewith V _mEbe respectively the east orientation speed of son, main inertial navigation; V _nwith V _mNbe respectively the north orientation speed of son, main inertial navigation; H and H _mbe respectively the course information of son, main inertial navigation, H can from sub-inertial navigation attitude matrix middle extracting directly.

System measurements equation is

Z(t)=H(t)X(t)+V(t) （5）

In formula, H (t) is measurement matrix, and V (t) is measurement noise, according to measuring vector and the relation of state vector, has measurement matrix to be

$H=\left[\begin{array}{cccccc}1& 0& 0& 0& 0& \\ 0& 1& 0& 0& 0& 0_{3\×3}\\ 0& 0& -\frac{T_{12}{T}_{32}}{T_{12}^2+T_{22}^2}& -\frac{T_{22}{T}_{32}}{T_{12}^2+T_{22}^2}& -1& \end{array}\right]$

System adopts Closed-cycle correction mode, and as shown in Figure 2, in information fusion process, what obtain is fed back to sub-inertial navigation system about velocity error, misalignment and gyro error and participates in computing.Complete circular navigation resolve with information fusion after, the t obtained ₁moment gyroscope error estimation value, namely as the estimated value of sub-inertial navigation system gyro error.

Illustrate gyroscope error estimation process of the present invention below:

1) at t ₀in the moment, utilize the position of main inertial navigation, speed carries out initialization to the corresponding navigation information of attitude information antithetical phrase inertial navigation, obtain the position of sub-inertial navigation, speed and attitude matrix t is time variable; Flash setting t ₀the carrier coordinate system in moment is b ₀, obtain i is (3 × 3) unit matrix;

2) in time period t ₀~ t ₁in, sub-inertial navigation carries out the collection of inertia type instrument data, storage, navigation calculation by cycle Δ t, and utilizes formula (6) to upgrade sub-inertial navigation carrier coordinate system b relative to b ₀the attitude matrix of system

$C_{{b,k}_1}^{b_0}=c_{{b,k}_1-1}^{b_0}(I+\mathrm{\Δt}{\mathrm{\ω}}_{{\mathrm{ib},k}_1}^b\×)---\left(6\right)$

In formula, subscript k ₁=1 ~ k _sum1represent the number of times label that navigation calculation upgrades, update times k ₁with attitude matrix variant time t be corresponding, for the data of sub-inertial navigation gyro Real-time Collection,

Sub-inertial navigation simultaneously receives the navigation information of autonomous inertial navigation by cycle Δ T and stores, and described navigation information comprises speed and course, and records the sequential relationship between main inertial navigation navigation information and sub-inertial navigation instrumented data; Main and sub inertial navigation Transfer Alignment is carried out by information fusion;

3) in step 2) terminate _tin 1 moment, obtain the real-time carrier matrix in this moment according to navigation calculation the carrier coordinate system in this moment of flash setting is b ₁, have

4) in time period t ₁~ t ₂in, sub-inertial navigation system works as follows:

41) to step 2) in the sub-inertial navigation inertia type instrument data that gather carry out m circular navigation and resolve and information fusion, t ₁~ t ₂inside carry out m circular navigation to resolve, as shown in Figure 3, each subcycle cycle is: t ₁₀~ t ₁₁, t ₂₀~ t ₂₁..., t _j0~ t _j1... t _m0~ t _m1, j=1 ~ m represents the label in subcycle cycle, in the navigation calculation and information fusion process of each subcycle, and sub-inertial navigation instrumented data used and main inertial navigation information corresponding t respectively ₀~ t ₁the navigation information of the instrumented data that interior sub-inertial navigation system gathers and main inertial navigation, within each subcycle cycle, navigation calculation update times and information fusion number of times and t ₀~ t ₁interior number of times is equal respectively, at each subcycle process t _j0~ t _j1in, instrumented data used and main inertial navigation information corresponding t respectively ₀~ t ₁in each collection point corresponding, its physical significance embodies t ₀~ t ₁the real-time of time period, but solution process takies t ₁~ t ₂the computer resource of time, namely each subcycle is all to t ₀~ t ₁the data of time period carry out navigation calculation, at t ₁~ t ₂inside carry out m time, in circulation solution process, naval vessel is in mooring or at the uniform velocity sails through to state, the speed of start time is resolved in each subcycle, a subcycle end cycle moment is directly got in position speed and position, but because boats and ships exist oscillating motion, the attitude that start time is resolved in each subcycle needs following process, at each subcycle t _j0~ t _j1start time t _j0initial attitude matrix:

$C_b^n\left(t_{j0}\right)=C_b^n\left(t_{(j-1)1}\right){\left(C_b^{b_0}\left(t_1\right)\right)}^T---\left(7\right)$

In formula, for at t _{(j-1) 1}the attitude matrix of the carrier coordinate system b Relative Navigation coordinate system n that the moment calculates, the i.e. sub attitude matrix at the end of resolving that circulates of jth-1,

Such as at t ₁₀~ t ₁₁in cycle period, t ₁₀for initial time, its initial attitude matrix can be calculated as follows:

$C_b^n\left(t_{10}\right)=C_{b_1}^n{C}_{b_0}^{b_1}=C_b^n\left(t_1\right)C_{b_0}^b\left(t_1\right)---\left(8\right)$

In formula, for at t ₁moment resolves the attitude matrix of the carrier coordinate system b Relative Navigation coordinate system n obtained.According to obtain after navigation calculation carry out next round circulation again to resolve, until obtain

In each subcycle process, by step 2) in record sequential relationship carry out navigation calculation and information fusion; At the end of circulation is resolved, namely at t ₂moment, because be to t ₀~ t ₁the data of time period carry out navigation calculation, and above-mentioned circular navigation is resolved and obtained attitude matrix real-time meaning correspond to t ₁moment, by resolve according to aforementioned buddy and obtain;

42) carry out above-mentioned circular navigation resolve with information fusion while, sub-inertial navigation carries out Real-time Collection to inertia type instrument data, upgrades and calculates present carrier coordinate system b system relative to b ₁the attitude matrix of system its discrete form is:

$C_{{b,k}_2}^{b_1}=c_{{b,k}_2-1}^{b_1}(I+\mathrm{\Δt}{\mathrm{\ω}}_{{\mathrm{ib},k}_2}^b\×)---\left(9\right)$

Wherein $C_{b,0}^{b_1}=C_b^{b_1}\left(t_1\right)=I,$ K ₂for number of times.Step 42) finally obtain k ₂the value upper limit jointly determined by cycle index m and computer main frequency.Time period t ₁~ t ₂interior step 41) and step 42) carry out, step 41 on the time) understand prior to step 42) complete simultaneously.

5) the circular navigation completing m cycle resolve and correspondence information fusion after, sub-inertial navigation system obtains t _m1moment carrier coordinate system b is relative to the Attitude estimation matrix of navigational coordinate system n i.e. t ₁the estimated value afterwards of moment attitude matrix, and t ₂moment, carrier coordinate system b was relative to b ₁real-time attitude matrix obtain t ₂the real-time attitude matrix in moment $C_b^n\left(t_2\right)=C_{b_1}^n{C}_b^{b_1}\left(t_2\right)=C_b^n\left(t_{m1}\right)C_b^{b_1}\left(t_2\right),$ For the navigation of sub-inertial navigation; Sub-inertial navigation simultaneously obtains t by the information fusion of the m time subcycle _m1the gyroscope error estimation value in moment, i.e. t ₁the estimated value afterwards of moment gyro error, by t _m1the gyroscope error estimation value in moment is as final gyroscope error estimation value;

T4) repeatedly above-mentioned steps T2 is carried out) and step T3), by the form of off-line simulation, select different time point t ₁, obtain different circular navigation and resolve period m, according to step 1)-5) gyro error is estimated fast, selecting can close to T1) in the t of estimation effect ₁with m as optimum time point t ₁with circular navigation computation cycles number m, estimation effect refers to T1 herein) the convergence effect of neutron inertial navigation gyro error convergence curve, formally for the Transfer Alignment of ship-borne master/sub inertial navigation, step 1)-5 is carried out in actual ship-borne master/sub inertial navigation Transfer Alignment process), realize gyro error and estimate fast.

Beneficial effect of the present invention is verified by following emulation:

1) Matlab simulates inertia type instrument data and main inertial guidance data

(1) generation of mooring condition Imitating data

Naval vessel, under mooring condition, does oscillating motion with sinusoidal rule around three axles, and its pitching, transverse direction and course are waved mathematical model and be:

In formula, θ, γ and ψ are respectively the angle variables in pitching, rolling and course; A _p, A _r, A _ybe respectively pitching, rolling and course wave amplitude; ω _p, ω _pwith ω _yrepresent the angle of oscillation frequency in pitching, rolling and course respectively; with pitching respectively, rolling and course initial phase; ψ ₀represent initial heading; ω _i=2 π/T _i, i=P, R, Y, T _irepresent corresponding rolling period.

Using above-mentioned emulated data and Additive White Noise as main inertial navigation information, main inertial navigation is 1s to the sampling period of described data.

Obtain sub-inertial navigation instrument gross data by above-mentioned emulated data simulation, and superpose corresponding site error thereon as instrument actual acquired data, sub-inertial navigation is sampled to described instrument actual acquired data, and for navigation calculation, the sampling period is 10ms.

The correlation parameter of emulation:

Naval vessel initial position: east longitude 118 °, north latitude 32 °;

Ship speed: 0m/s;

Ship sway amplitude: pitching 9 °, rolling 14 °, boat shake 12 °;

The ship sway cycle: pitching 8s, rolling 10s, boat shake 6s;

Ship sway initial phase: be 0;

Initial heading, naval vessel: 0 °;

Equatorial radius: 6378165m;

Earth ellipsoid degree: 1/298.3;

Earth surface acceleration of gravity: 9.8m/s ²;

Rotational-angular velocity of the earth: 15.04088 °/h;

Gyroscope constant value error: 0.5 °/h;

Gyro white noise error: 0.5 °/h;

Accelerometer bias: 500ug;

Accelerometer white noise error: 500ug;

Main inertial navigation system measures white noise parameter: east/north orientation velocity error variance 0.2m/s, course error variance 0.15 °/h.

(2) generation of condition Imitating data is at the uniform velocity sailed through to

Under at the uniform velocity direct route condition, correlation parameter is identical with mooring condition, and difference is: ship speed is 10m/s.

2) mathematical verification on navigational computer

The navigational computer of x-86 structure adopts respectively two schemes verify, scheme one: classical Transfer Alignment, be namely that order carries out instrumented data collection, navigation calculation with time, and carry out information fusion when there being main inertial navigation measurement information; Scheme two: the rapid alignment algorithm adopting the present invention's design, wherein data store 120s, i.e. t ₁=120s.Compare the alignment precision of two schemes and the time of aiming at respectively.

The curve of Fig. 4 and Fig. 5 shows, under mooring condition, the alignment precision of two schemes is suitable, also suitable to the estimation of gyro error.Fig. 6 and Fig. 7 shows, under at the uniform velocity direct route condition, the alignment precision of two schemes is suitable, also suitable to the estimation of gyro error.

But the aligning time difference that two schemes is used.

For scheme one, abscissa representing time in Fig. 4 ~ 7, under mooring with at the uniform velocity direct route condition, scheme one completes needs about 200s to the estimation of misalignment, and approximately needs 600s to the estimation of gyro error.

For scheme two, in Fig. 4 ~ 7, horizontal ordinate represents iterations, completes and needs iterations 20000 times to the estimation of misalignment, completes and approximately needs 60000 times to the estimation of gyro error.Consuming time to complete iteration No. 60000 anacoms, wherein first 12000 times, need to store inertia type instrument data and main inertial navigation metric data, 120s consuming time, this is consuming time identical with scheme one; But amount to 480000 at 12001 ~ 60000() secondary, the time used is determined by computer speed.

In this emulation, computer main frequency 333MHz used.This type computing machine complete a navigation calculation and or need time 1ms; Complete separately and once complete or need about 0.2ms; Complete primary information fusion and need 25ms.In 48000 navigation upgrade, need to carry out information fusion 480 times, navigation upgrades 38.4s consuming time, information fusion 12s consuming time, amounts to 50.4s consuming time.In loop calculation, computing machine needs upgrade and system task scheduling overhead, computing machine actual measurement 59.2s consuming time.Whole alignment procedures 120+59.2=179.2s consuming time, i.e. t ₂=179.2s, to the estimated time of gyro error of the 600s much smaller than scheme one.

Therefore the method for the present invention's design is suitable with classical alignment scheme on alignment precision, but is significantly improved to the estimating speed of gyro error.

Claims (4)

1. the gyro error method for quick estimating in a ship-borne master/sub inertial navigation Transfer Alignment process, it is characterized in that estimating fast gyroscope constant value error under the support of real-time multi-task operating system, in master/sub-inertial navigation Transfer Alignment process, navigation calculation is carried out in sub-inertial navigation, sub-inertial navigation utilizes the navigation data of main inertial navigation to carry out information fusion, if t ₀for the initial time of gyroscope constant value estimation of error, be also the initial time of initial alignment, t ₀~ t ₁for data acquisition, data storage, real-time navigation resolve and information fusion and attitude matrix update time section, t ₁~ t ₂for based on t ₀~ t ₁between store information circular navigation resolve and information fusion and attitude matrix update time section, the determination of above-mentioned each time is as follows:

T1) for concrete sub-inertial navigation system, leading/sub-inertial navigation Transfer Alignment in, the time required for whole aligning has been determined by sub-inertial navigation gyro error convergence curve, again according to sub-inertial navigation measurement and navigation calculation update cycle Δ t, determine the total update times of navigation calculation required for whole aligning, be set as k _sum; According to main inertial navigation navigation information updating cycle Δ T, determined the information fusion number of times required for whole aligning, Δ T is the information fusion cycle; Under the working environment determined, navigation calculation and information fusion sequential relationship are determined, after navigation calculation number of times is determined, information fusion number of times can be determined;

T2) according to sub-inertial navigation instrumented data quality, main inertial navigation measurement information quality, setting moment t ₁and time period t ₀~ t ₁, and calculate navigation calculation update times in this time period according to Δ t, be set as k _sum1;

T3) from the total update times k of navigation calculation required for whole aligning _sumin, deduction step T2) middle t ₀~ t ₁navigation calculation update times k in time period _sum1, obtained the navigation calculation update times that whole aligning has also needed, be set as k _sum2, k _sum2=k _sum-k _sum1, thus obtain t ₁~ t ₂the circular navigation of time period resolves cycle index, is set as m, m=k _sum2/ k _sum1, when m is not integer, by m value upwards rounding, and according to the m value adjustment k after rounding _sum2; Moment t ₂the performance being resolved cycle index m and navigational computer by circular navigation is determined jointly, and when m determines, navigational computer dominant frequency is higher, t ₂with t ₁between difference less;

According to the described time determined, in Transfer Alignment, complete sub-inertial navigation gyroscope error estimation, comprise the steps:

1) at t ₀in the moment, utilize the position of main inertial navigation, speed carries out initialization to the corresponding navigation information of attitude information antithetical phrase inertial navigation, obtain the position of sub-inertial navigation, speed and attitude matrix t is time variable; Flash setting t ₀the carrier coordinate system in moment is b ₀, obtain i is (3 × 3) unit matrix;

2) in time period t ₀~ t ₁in, sub-inertial navigation carries out the collection of inertia type instrument data, storage, navigation calculation by cycle Δ t, and utilizes formula (1) to upgrade sub-inertial navigation carrier coordinate system b relative to b ₀the attitude matrix of system

In formula, subscript k ₁=1 ~ k _sum1represent the number of times label that navigation calculation upgrades, for the data of sub-inertial navigation gyro Real-time Collection, operational symbol "×" represents vectorial backslash computing;

Sub-inertial navigation simultaneously receives the navigation information of autonomous inertial navigation according to cycle Δ T and stores, and described navigation information comprises speed and course, and records the sequential relationship between main inertial navigation navigation information and sub-inertial navigation instrumented data; Main and sub inertial navigation Transfer Alignment is carried out by information fusion;

3) in step 2) terminate t ₁in the moment, obtain the real-time carrier matrix in this moment the carrier coordinate system in this moment of flash setting is b ₁, have

4) in time period t ₁~ t ₂in, sub-inertial navigation system works as follows:

41) to step 2) in the sub-inertial navigation inertia type instrument data that gather carry out m circular navigation and resolve and information fusion, t ₁~ t ₂inside carry out m circular navigation to resolve, each subcycle cycle is: t ₁₀~ t ₁₁, t ₂₀~ t ₂₁, t _j0~ t _j1, t _m0~ t _m1, j=1 ~ m represents the label in subcycle cycle, in the navigation calculation and information fusion process of each subcycle, and sub-inertial navigation instrumented data used and main inertial navigation information corresponding t respectively ₀~ t ₁the navigation information of the instrumented data that interior sub-inertial navigation system gathers and main inertial navigation, within each subcycle cycle, navigation calculation update times and information fusion number of times and t ₀~ t ₁interior number of times is equal respectively; In circulation solution process, naval vessel is in mooring or at the uniform velocity sails through to state, the speed of start time is resolved in each subcycle, a subcycle end cycle moment is directly got in position speed and position, but because boats and ships exist oscillating motion, the attitude that start time is resolved in each subcycle needs following process, at each subcycle t _j0~ t _j1start time t _j0initial attitude matrix:

In formula, for at t _{(j-1) 1}the attitude matrix of the carrier coordinate system b Relative Navigation coordinate system n that the moment calculates, the i.e. sub attitude matrix at the end of resolving that circulates of jth-1,

In each subcycle process, by step 2) in record sequential relationship carry out navigation calculation and information fusion;

42) carry out above-mentioned circular navigation resolve with information fusion while, sub-inertial navigation carries out Real-time Collection to inertia type instrument data, upgrades and calculates present carrier coordinate system b system relative to b ₁the attitude matrix of system its discrete form is:

Wherein k ₂for update times, operational symbol "×" represents vectorial backslash computing, step 42) finally obtain

5) the circular navigation completing m cycle resolve and correspondence information fusion after, sub-inertial navigation system is according to t _m1moment carrier coordinate system b is relative to the Attitude estimation matrix of navigational coordinate system n i.e. t ₁the estimated value afterwards of moment attitude matrix, and t ₂moment, carrier coordinate system b was relative to b ₁real-time attitude matrix obtain t ₂the real-time attitude matrix in moment for the navigation of sub-inertial navigation; Sub-inertial navigation simultaneously obtains t _m1the gyroscope error estimation value in moment, i.e. t ₁the estimated value afterwards of moment gyro error, by t _m1the gyroscope error estimation value in moment is as final gyroscope error estimation value;

T4) repeatedly above-mentioned steps T2 is carried out) and step T3), by the form of off-line simulation, select different time point t ₁, obtain different circular navigation and resolve period m, according to step 1)-5) gyro error is estimated fast, selecting can close to T1) in the t of estimation effect ₁with m as optimum time point t ₁with circular navigation computation cycles number m, formally for the Transfer Alignment of ship-borne master/sub inertial navigation, described estimation effect refers to T1) the convergence effect of neutron inertial navigation gyro error convergence curve; In actual ship-borne master/sub inertial navigation Transfer Alignment process, carry out step 1)-5), realize gyro error and estimate fast.

2. the gyro error method for quick estimating in a kind of ship-borne master/sub inertial navigation Transfer Alignment process according to claim 1, it is characterized in that described real-time multi-task operating system is multiple task real-time operation system VxWorks, complete following four tasks, the scheduling of task is automatically performed by the priority level of multiple task real-time operation system VxWorks according to task, four tasks below running in sub-inertial navigation:

1) task one: sub-inertial navigation instrumented data gathers, store and navigation calculation and more new Algorithm, priority level is the highest;

2) task two: sub-inertial navigation instrumented data gathers, more new Algorithm, priority level second;

3) task three: sub-inertial navigation carries out data acquisition, storage and information fusion to main inertial navigation, priority level the 3rd;

Task four: sub-inertial navigation is resolved and information fusion based on the circular navigation storing data, and priority level is minimum.

3. the gyro error in a kind of ship-borne master/sub inertial navigation Transfer Alignment process according to claim 1 and 2

Method for quick estimating, is characterized in that in Transfer Alignment process, and the navigation computation of sub-inertial navigation is:

In formula, for the attitude matrix of sub-inertial navigation carrier coordinate system b Relative Navigation coordinate system n, I is (3 × 3) unit matrix, and subscript k=1 ~+∞ represents the update times label of navigation calculation, n represents navigational coordinate system, b represents carrier coordinate system, and i represents inertial coordinates system represent that terrestrial coordinate system e is relative to the projected angle speed of inertial coordinates system i in navigational coordinate system n, represent that navigational coordinate system n is relative to the projected angle speed of terrestrial coordinate system e in navigational coordinate system n; In formula (4) for sub-inertial navigation gyro image data, be respectively the east of sub-inertial navigation, north, sky to speed, L, λ and h represent speed, latitude, longitude and height under navigational coordinate system respectively, f ^bfor sub-inertial navigation accelerometer image data, g ⁿfor the projection of terrestrial gravitation acceleration in navigational coordinate system, R _mand R _nbe respectively meridian circle and the prime vertical radius of the navigation location earth, operational symbol "×" represents vectorial backslash computing, under carrier-borne environment, directly get sub-inertial navigation sky to speed be highly zero.

4. the gyro error method for quick estimating in a kind of ship-borne master/sub inertial navigation Transfer Alignment process according to claim 1 and 2, is characterized in that, in Transfer Alignment process, main and sub inertial navigation information is fused to:

Adopt Kalman filter as information fusion filtering device, get sub-inertial navigation east orientation/north orientation velocity error, misalignment and gyro error as system state vector, namely

X＝[δV _EδV _Nφ _Eφ _Nφ _Uε _xε _yε _z] ^T

Wherein, δ V _e/ δ V _nfor east orientation/north orientation velocity error; φ _e, φ _n, φ _ube respectively pitching, rolling, course misalignment; ε _x, ε _y, ε _zbe respectively three axle gyro errors;

Get system state equation,

In formula, A (t) is state matrix, and W (t) is system noise, according to system state variables medium velocity, misalignment error equation, and gyro is from the projection relation of carrier coordinate system b navigation coordinate system n, state matrix A (t) is expressed as:

Wherein, V _e, V _nfor sub-inertial navigation east orientation and north orientation speed, ω _iefor rotational-angular velocity of the earth, R is earth radius, and L is local geographic latitude, f _e, f _n, f _ube respectively sub-inertial navigation acceleration measurement f ^bprojection in navigational coordinate system n, T _pq, p, q=1,2,3 is the attitude matrix of sub-inertial navigation carrier coordinate system b Relative Navigation coordinate system n each element;

" speed+course " the information matches mode of employing, get son, the speed of main inertial navigation, course difference directly construct measurement information, i.e. son/main inertial navigation navigational system measures vector and is

Z＝[V _E-V _MEV _N-V _MNH-H _M] ^T

Wherein, V _ewith V _mEbe respectively the east orientation speed of son, main inertial navigation; V _nwith V _mNbe respectively the north orientation speed of son, main inertial navigation; H and H _mbe respectively the course information of son, main inertial navigation, H is from sub-inertial navigation attitude matrix middle extracting directly;

System measurements equation is

Z(t)＝H(t)X(t)+V(t) (8)

In formula, H (t) is measurement matrix, and V (t) is measurement noise, according to measuring vector and the relation of state vector, has measurement matrix to be

In information fusion process, adopt Closed-cycle correction mode, information fusion is estimated velocity error, misalignment and the gyroscope error estimation value obtained feeds back to sub-inertial navigation system and participate in navigation calculation.