CN102213594A - Method for fusing ocean current observation data of unmanned undersea vehicle (UUV) - Google Patents

Abstract

The invention provides a method for fusing ocean current observation data of an unmanned underwater vehicle. 1. Ocean current profile data acquisition, when the UUV is sailing at a certain depth underwater, the ocean current profile of a certain water layer thickness above or below the UUV is obtained; 2, Ocean current profile data filtering, the original data of the ocean current profile is filtered to eliminate outliers, And smooth corrections are made to the random errors of measurement; 3. Time registration of ocean current profile data, and asynchronous data are reduced to synchronous data at the same time; 4. Calculation of UUV position information, UUV starts from a known coordinate position, According to the heading, speed and sailing time of the UUV at this point, the coordinate position at the next moment is estimated; 5. The ocean current profile data fusion converts the longitude and latitude position information obtained from the position information calculation into ASCII codes, and inserts them into the corresponding ADCP data packet Location. The invention can obtain accurate and complete ocean current profile information under the geodetic coordinate system.

Description

A Fusion Method for Unmanned Submarine Vehicle Current Observation Data

technical field

The invention relates to a method for processing marine observation data of an underwater unmanned vehicle.

Background technique

Unmanned Underwater Vehicles (UUV for short), also known as unmanned underwater vehicles or underwater robots, is a kind of unmanned intelligent small equipment that uses surface ships as a support platform and can sail autonomously and long-distance underwater for a long time. platform. UUV carries the Doppler current profiler (Acoustic Doppler Current Profile, referred to as ADCP) current measurement method, which belongs to the underwater self-propelled ocean observation technology. It overcomes the shortcomings of the traditional bottom-seat self-contained current monitoring method, such as the small observation range and difficulty in deployment and recovery, and also overcomes the defects that surface ships are seriously affected by the sea environment when carrying ADCP to observe currents, and cannot observe deep-sea currents. However, when UUV carries ADCP to measure ocean currents underwater, it cannot receive GPS signals, resulting in inaccurate and comprehensive ocean current information due to lack of geographic location information. However, in domestic and foreign literature, there is no report on the data fusion of the measured ocean current profile data when the UUV is equipped with ADCP for underwater navigation.

Contents of the invention

The purpose of the present invention is to provide a method for fusion of unmanned submersible vehicle ocean current observation data that can obtain accurate and complete ocean current profile information under the geodetic coordinate system.

The purpose of the present invention is achieved like this:

1. Ocean current profile data acquisition

UUV is composed of shell, thruster, DVL, ADCP, attitude sensor, compass, GPS and control computer. When UUV sails at a certain depth underwater, ADCP emits sound waves of a certain frequency under the control of the control computer, and uses the Doppler effect to obtain The current profile of a certain water layer thickness above or below the UUV;

2. Ocean current profile data filtering

Filter the obtained raw data of the ocean current profile, eliminate the outliers, and smooth out the random error of the measurement;

3. Time registration of ocean current profile data

Before the fusion of ocean current observation data, the filtered asynchronous data is reduced to synchronous data at the same time;

4. Calculation of UUV position information

UUV starts from a known coordinate position, and calculates the coordinate position at the next moment according to the course, speed and sailing time of the UUV at this point;

5. Ocean current profile data fusion

The longitude and latitude position information calculated by the position information is converted into ASCII code, inserted into the corresponding position of the ADCP data packet, and the fusion of position information and ocean current data is completed after updating the packet length and check code.

In order to solve the problem that the UUV carrying ADCP cannot receive GPS signals in real time when measuring ocean currents underwater, resulting in inaccurate and comprehensive ocean current information due to lack of geographical location information, this invention proposes a UUV self-information and ocean current data Fusion method to obtain accurate and complete ocean current profile information in the geodetic coordinate system.

In order to obtain continuous and stable ocean current profile data, the present invention designs an ADCP platform, that is, UUV. UUV mainly consists of shell, propeller, DVL, ADCP, attitude sensor, compass, GPS and control computer. During deep navigation, the ADCP (transducer head installed upward or downward) emits sound waves of a certain frequency under the control of the control computer, and uses the Doppler effect to obtain the ocean current profile of a certain water layer thickness above or below the UUV.

In the process of UUV carrying ADCP to measure ocean currents, due to the self-noise of the instrument, sea state factors, sonar installation deviation and unreasonable parameter settings, as well as errors in attitude, compass and other sensors, especially when there are moving fish or ocean in the water layer When biological, the ocean current observation data contains abnormal data (outlier values) and random errors. When the present invention performs post-processing on ocean current observation data, these original data are filtered, outliers are eliminated, random errors in measurement are smoothly corrected, and the accuracy of ocean current data is improved.

Since the DVL, attitude sensor, compass and other sensors are difficult to be completely synchronized in terms of sampling start time, sampling frequency, and transmission delay, the measured ocean current data, UUV speed and heading data are often asynchronous before fusion. In the present invention, these asynchronous data are reduced to synchronous data at the same time before the fusion of ocean current observation data, and this processing process is called ocean current profile information time registration.

When UUV is sailing underwater, GPS cannot receive real-time position information. In order to obtain UUV latitude and longitude information, it is necessary to calculate and estimate the position of UUV. Here, the method of ship position calculation is adopted: UUV starts from a known coordinate position, according to The course, speed and sailing time of the UUV at this point are used to calculate the coordinate position at the next moment.

The ocean current profile data obtained by UUV underwater navigation does not contain the corresponding longitude and latitude position information. In order to obtain accurate and comprehensive ocean current profile data, the present invention fuses the UUV latitude and longitude position information with the ocean current profile information: calculate the longitude and latitude of the ship position The position information is converted into ASCII code, inserted into the corresponding position of the ADCP data packet, and the fusion of position information and ocean current data is completed after updating the packet length and check code.

The present invention has following advantage and effect relative to prior art:

The present invention can realize the data fusion of the ocean current profile obtained by the UUV-mounted ADCP and the UUV position information, thereby obtaining comprehensive, stable and reliable ocean current information.

Description of drawings

Fig. 1 is the schematic diagram of the ocean current observation number fusion process of the present invention;

Fig. 2 is a UUV composition block diagram of the present invention;

Fig. 3 is a schematic diagram of UUV position estimation of the present invention;

Fig. 4 is a schematic diagram of the time registration scheme of ocean current information of the present invention;

Fig. 5 is the result of WinRiver processing of the fused ocean current profile information of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Accompanying drawing 2 is a schematic diagram of the composition of the UUV system of the present invention, 1 is the thruster, 2 is the DVL, 3 is the ADCP, 4 is the attitude sensor, 5 is the compass, 6 is the control computer, 7 is the GPS, and 8 is the UUV shell.

Fig. 3 is a schematic diagram of the principle of UUV position estimation in the present invention, wherein the initial latitude and longitude (J ₀ , W ₀ ) refers to the GPS latitude and longitude recorded at the initial moment when the position is estimated, and (J, W) is where the UUV is at any time when the UUV position is estimated. Location.

1. Ocean current profile data acquisition

By designing a UUV (as shown in Figure 1) to obtain the current profile information of the observed sea area, the UUV mainly consists of a shell, propeller, DVL, ADCP, attitude sensor, compass, GPS and control computer. The UUV is underwater at a certain depth. When sailing, ADCP (transducer head installed upwards or downwards) under the control of the control computer emits sound waves of a certain frequency, and the Doppler effect can be used to obtain the ocean current profile data of a certain water layer thickness above or below the UUV, and the ocean current profile data It is transmitted to the storage medium of the control computer through the serial port (or network port) for storage, so that the ocean current profile data can be obtained through the UUV.

2. Ocean current observation data filtering

In the process of UUV carrying ADCP to measure ocean currents, due to the self-noise of the instrument, sea state factors, sonar installation deviation and unreasonable parameter settings, as well as errors in attitude, compass and other sensors, especially when there are moving fish or ocean in the water layer When biological, the ocean current observation data contains abnormal data (outlier values) and random errors. Therefore, when post-processing the ocean current observation data, it is necessary to filter these raw data, eliminate outliers, and smooth the random error of measurement to improve the accuracy of the ocean current data.

(1) Outlier elimination of ocean current data based on polynomial fitting

The outlier elimination method based on polynomial fitting needs to fit a polynomial to the known ocean current observation data, and then use the mean square error criterion of the triple fitting residual sequence to discriminate and eliminate, which is easier to operate than other methods. The steps of this method to eliminate the outlier value of ocean current observation data are as follows:

① Carry out least squares polynomial fitting on the known ocean current observation data (t _i , y _i ), i=0, 1, ..., m, appropriate number n, where t _i is the ocean current measurement time, y _i is the ocean current velocity;

② Calculate the coefficient matrix α ₀ , α ₁ , , α _n to get the fitting polynomial

③Calculate the corresponding fitting value sequence p _i : i=1, 2, ·, m;

④ Generate a fitting residual sequence Δy _i =p _i -y _i , i=1, 2, , m;

⑤ Calculate the mean square error σ of the fitted residual sequence:

$\mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; =</span>\sqrt{\frac{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; m</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

⑥ Use the 3σ criterion to judge and eliminate outliers, and the data after eliminating outliers is y′ _i : i=1, 2, , m:

When |Δy _i |<3σ:

y′ _i =y _i (2)

When |Δy _i |＞3σ:

y _i ＝(y _i-3 +y _i-2 +y _i-1 +y _i+1 +y _i+2 +y _i+3 )/6 (3)

According to formula (2) and formula (3), if the residual value is less than the threshold value, it is a normal value, and this value remains unchanged; if it is greater than or equal to the threshold value, it is judged as an outlier value, and the six adjacent The mean of the data is used to replace the wild value. The threshold value 3σ can be changed appropriately according to the specific situation of the experiment.

(2) Ocean current data smoothing based on wavelet decomposition and reconstruction

After eliminating the outliers, although the outliers in the data are gone, the ADCP carried by the UUV is affected by various errors in the water scatterers and the system in actual measurement, which brings certain random errors to the measurement data, especially ocean currents. For non-stationary signals such as data, there will be large signal jumps. Therefore, the main problem facing the processing of Doppler measurement data is how to choose an effective data smoothing method. Wavelet decomposition and reconstruction technology is a new data smoothing method with a wide range of applications. It has the details of retaining information while eliminating high-frequency noise. The data is smoothed. The smoothing of ocean current data based on wavelet decomposition and reconstruction is to decompose the data by using the multi-resolution characteristics in the wavelet transform, and realize the layer-by-layer decomposition of the data through the multi-resolution signal algorithm proposed by Mallat, and finally obtain the low-frequency information of the original signal .

3. Time registration of ocean current observation data

Since the DVL, attitude sensor, compass and other sensors are difficult to be completely synchronized in terms of sampling start time, sampling frequency, and transmission delay, the measured ocean current data, UUV speed and heading data are often asynchronous before fusion. Therefore, these asynchronous data need to be reduced to synchronous data at the same time before the fusion of ocean current observation data. This process is called time registration of ocean current profile information.

The present invention adopts a time registration scheme based on linear interpolation. The basic principle of linear interpolation is to estimate the value at the corresponding low-precision time point on high-precision observation data, take three sets of observation data in the same processing cycle, and use linear Interpolation method to establish a temporal registration scheme. The three data sources that need time registration are in ascending order of measurement accuracy: UUV velocity data, UUV heading data, and sea current velocity data. The specific process is shown in Figure 4.

① Define an array and assign values, respectively t[], y[], where t[] is the measurement time of the ocean current, and y[] is the velocity of the ocean current;

②Input the value point T of the function to be found;

③ Search the position of T in the t array, and find the interpolation nodes t _i and t _i+1 adjacent to T, where t _i ≤ T ≤ _{t i+1} ;

④Find the corresponding interpolation nodes y _i and y _i+1 of y, and use every two adjacent interpolation base points for linear interpolation to obtain the following linear interpolation function:

4. Calculation of UUV position information

When UUV is sailing, the speed measured by DVL is generally the speed in the hull coordinate system. In order to calculate the longitude and latitude of the carrier when UUV sails, it is necessary to convert the speed of UUV in the hull coordinate system to the speed in the northeast coordinate system. The components of the UUV carrier speed in the direction of due east and due north are calculated as follows:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; E.</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; h</span>}\\ {\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; h</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

In the formula, v _E and v _N —— are the components of the carrier's navigation speed in the direction of due east and due north respectively;

v _F , v _L ——respectively, the forward velocity and leftward velocity of the carrier relative to the ground measured by DVL;

H——The heading angle of the UUV carrier, clockwise is positive and counterclockwise is negative, which can be measured by the compass.

Combined with Figure 3, the longitude and latitude of UUV carrier navigation can be calculated by formula (5):

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; J</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}\\ \mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

In the formula, Δt——DVL sampling period;

J, W——respectively the longitude and latitude of the UUV carrier's location at n time;

J ₀ , W ₀ ——respectively, the longitude and latitude of the carrier at the initial moment, which can be measured by the GPS receiver;

v _{E, (i-1)} , v _{N, (i-1)} ——respectively the components of UUV navigation speed in the direction of due east and due north at time i-1;

R _{M, (i-1)} , R _{N, (i-1)} ——respectively, the radius of curvature of the earth's meridian and the radius of curvature of the latitude circle at time i-1.

5. Ocean current profile information data fusion

Data fusion is mainly to fuse the UUV's own information (attitude, heading, navigation speed, position) and ocean current profile information at the data level; convert the UUV's attitude, heading, navigation speed, position and other information into ASCII codes, after the first four After the steps are processed, it is fused to the corresponding position in the ocean current profile information data packet, and after updating the packet length and check code, the fusion of position information and ocean current data is completed. Open the fused ocean current profile data package with the ocean current post-processing software WinRiver software, and you can intuitively get the size and direction of the ocean current profile at any position.

Fig. 5 is the use of the ADCP sensor carried by the UUV of the present invention to measure and observe the ocean current profile information in a certain area when sailing underwater at 7m, and use the WinRiver software to process the results of the fusion of the ocean current profile data. It can be seen intuitively from Fig. 5 The magnitude and direction of ocean currents.

Claims (5)

1. autonomous underwater vehicle ocean current observation data fusion method is characterized in that:

(1) the ocean current profile data are obtained

Form UUV by shell, thruster, DVL, ADCP, attitude sensor, compass, GPS and control computer, UUV is certain depth when navigation under water, ADCP is under control computer control, the sound wave of emission certain frequency utilizes Doppler effect to obtain the ocean current profile of the certain water layer thickness in UUV top or bottom;

(2) ocean current profile data filtering

The ocean current profile raw data of obtaining is carried out filtering, eliminate wild value, and random deviation of measurement is smoothly revised;

(3) ocean current profile data time registration

The synchrodata of inscribing in the time of before the ocean current observation data is merged, will being identical through the asynchronous data reduction of Filtering Processing;

(4) reckoning of UUV positional information

UUV according to course, the speed of a ship or plane and the hours underway of UUV at this point, calculates next coordinate position constantly since a known coordinate position;

(5) ocean current profile data fusion

Convert the longitude and latitude positional information of the reckoning gained of positional information to ASCII character, be inserted into the relevant position of ADCP packet, update package long with check code after the fusion of completing place information and ocean current data.

2. a kind of autonomous underwater vehicle ocean current observation data fusion method according to claim 1 is characterized in that:

The described open country value of eliminating is the ocean current data method of abnormal value removing and correction of employing based on fitting of a polynomial, and step is as follows:

1. to known ocean current observation data (t _i, y _i), i=0,1 ..., m, suitable frequency n is carried out least square polynomial fit, wherein t _iBe ocean current measurement time, y _iBe the current speed size;

2. obtain matrix of coefficients α ₀, α ₁,, α _n, obtain polynomial fitting

3. calculate corresponding match value sequence p _i: i=1,2,, m;

4. generate match residual sequence Δ y _i=p _i-y _i, i=1,2,, m;

5. calculate the square error σ of match residual sequence:

$\mathrm{\&sigma;}=\sqrt{\frac{{\mathrm{\&Delta;y}}_1^2+{\mathrm{\&Delta;y}}_2^2+\&CenterDot;+{\mathrm{\&Delta;y}}_m^2}{m}}$

6. utilize 3 σ criterions to judge and the wild value of rejecting that the data after the wild value of rejecting are y ' _i: i=1,2,, m:

When | Δ y _i| during＜3 σ:

y′ _i＝y _i

When | Δ y _i| during＞3 σ:

y _i＝(y _i-3+y _i-2+y _i-1+y _i+1+y _i+2+y _i+3)/6

According to formula y ' _i=y _iWith formula y _i=(y _I-3+ y _I-2+ y _I-1+ y _I+1+ y _I+2+ y _I+3)/6 are if residual values is less than threshold value, for just

Normal value, this value is constant; If more than or equal to threshold value, then be judged as wild value, use the average of six data that are adjacent to replace this wild value;

Described level and smooth correction is based on the ocean current data smoothing of wavelet decomposition and reconstruct.

3. a kind of autonomous underwater vehicle ocean current observation data fusion method according to claim 1 and 2 is characterized in that: the synchrodata of inscribing when described asynchronous data reduction is identical is the temporal registration scheme that adopts based on linear interpolation, and detailed process is:

1. define arrays and assignment, be respectively t[], y[], t[wherein] be ocean current measurement time, y[] be the current speed size;

2. input waits to ask functional value point T;

3. the contiguous interpolation knot t of T is found in the position of search T in the t array _i, t _I+1, t wherein _i≤ T≤t _I+1

4. find the interpolation knot y of corresponding y _iAnd y _I+1, utilize per two adjacent interpolation basic points to make linear interpolation, obtain following linear interpolation function:

4. a kind of autonomous underwater vehicle ocean current observation data fusion method according to claim 1 and 2 is characterized in that UUV carrier headway at the component calculation method of due east direction and direct north is:

$\left\{\begin{array}{c}{v}_E=v_F\sin H-v_L\cos H\\ v_N=v_F\cos H+v_L\sin H\end{array}\right.$

V in the formula _E, v _N---be respectively the component of carrier headway at due east direction and direct north;

v _F, v _L---be respectively carrier forward speed and the left-hand speed relative to the earth that DVL records;

H---the course angle of UUV carrier clockwise for just, is recorded by compass;

Longitude and latitude is calculated by following formula in the navigation of UUV carrier:

$\left\{\begin{array}{c}J=J_0+\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{v}_{E,(i-1)}\mathrm{\&Delta;t}/R_{M,(i-1)}\\ W=W_0+\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{v}_{N,(i-1)}\mathrm{\&Delta;t}/R_{N,(i-1)}\end{array}\right.$

Δ t in the formula---the DVL sampling period;

J, W---be respectively the n longitude and the latitude of UUV carrier position constantly;

J ₀, W ₀---be respectively the longitude and the latitude of initial time carrier, record by the GPS receiver;

v _{E, (i-1)}, v _{N, (i-1)}---be respectively the component of i-1 moment UUV headway at due east direction and direct north;

R _{M, (i-1)}, R _{N, (i-1)}---be respectively i-1 earth meridian radius-of-curvature and latitude circle radius-of-curvature constantly.

5. a kind of autonomous underwater vehicle ocean current observation data fusion method according to claim 3 is characterized in that UUV carrier headway at the component calculation method of due east direction and direct north is:

$\left\{\begin{array}{c}{v}_E=v_F\sin H-v_L\cos H\\ v_N=v_F\cos H+v_L\sin H\end{array}\right.$

V in the formula _E, v _N---be respectively the component of carrier headway at due east direction and direct north;

v _F, v _L---be respectively carrier forward speed and the left-hand speed relative to the earth that DVL records;

H---the course angle of UUV carrier clockwise for just, is recorded by compass;

Longitude and latitude is calculated by following formula in the navigation of UUV carrier:

$\left\{\begin{array}{c}J=J_0+\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{v}_{E,(i-1)}\mathrm{\&Delta;t}/R_{M,(i-1)}\\ W=W_0+\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{v}_{N,(i-1)}\mathrm{\&Delta;t}/R_{N,(i-1)}\end{array}\right.$

Δ t in the formula---the DVL sampling period;

J, W---be respectively the n longitude and the latitude of UUV carrier position constantly;

J ₀, W ₀---be respectively the longitude and the latitude of initial time carrier, record by the GPS receiver;

v _{E, (i-1)}, v _{N, (i-1)}---be respectively the component of i-1 moment UUV headway at due east direction and direct north;

R _{M, (i-1)}, R _{N, (i-1)}---be respectively i-1 earth meridian radius-of-curvature and latitude circle radius-of-curvature constantly.

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