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 undersea vehicle (UUV), which comprises the following steps of: 1, obtaining ocean current profile data, when the UUV underwater navigates at a certain depth, obtaining an ocean current profile with a certain water layer thickness at the upper part or lower part of the UUV; 2, filtering the ocean current profile data, filtering the obtained ocean current original data, eliminating a wild value, carrying out smooth correction on a measured random error; 3, carrying out time registering on the ocean current profile data, reducing asynchronous data into synchronous data under the same time moment; and 4, reducing position information of the UUV, starting from one known coordinate position of the UUV to reduce a coordinate position of the next time according to the navigation direction, the navigation speed and the navigation time of the UUV at the coordinate position; and 5, fusing the ocean current profile data, converting longitude and latitude position information obtained from the reduction of the position information into ASCII (American Standard Code For Information Interchange) codes, and inserting into corresponding positions of an ADCP (Acoustic Doppler Current Profiler) data packet. According to the invention, accurate and complete ocean current profile information can be obtained under a geodetic coordinate system.

Description

A kind of autonomous underwater vehicle ocean current observation data fusion method

Technical field

What the present invention relates to is a kind of unmanned under water aircraft oceanographic observation data processing method.

Background technology

Autonomous underwater vehicle (Unmanned Underwater Vehicles, be called for short UUV) claims unmanned submarine navigation device or underwater robot again, be a kind of be to support platform with the above water craft, can be for a long time the unmanned intelligent small-sized equipment platform of autonomous long voyage under water.UUV carries Doppler's ocean current profile instrument (Acoustic Doppler Current Profile, be called for short ADCP) the ocean current measurement method, belong to self-propulsion type ocean observation technology under water, this ocean current observation procedure can hiddenly be observed, not influenced by the sea stormy waves, can realize characteristics such as all weather operations, it is little to have overcome at the bottom of traditional seat the observation scope of self-tolerant ocean current monitoring mode, lay the deficiency that reclaims difficulty, also having overcome when above water craft carries ADCP observation ocean current is subjected to the sea environmental impact serious, can not be to the defective of deep-sea ocean current observation, and UUV carries and can not receive gps signal when ADCP measures ocean current under water, thereby causes ocean current information to become not accurate enough and comprehensive because of the disappearance geographical location information.And when carrying ADCP and navigate by water under water for UUV in the domestic and foreign literature, the ocean current profile data that record do not have the relevant report of it being carried out data fusion.

Summary of the invention

The object of the present invention is to provide a kind of can obtaining under earth coordinates, the autonomous underwater vehicle ocean current observation data fusion method of accurate, complete ocean current profile information.

The object of the present invention is achieved like this:

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.UUV the reckoning of 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.

When carrying ADCP and measure ocean current under water, UUV can not receive gps signal in order to solve in real time, thereby cause ocean current information because of disappearance the geographical location information not accurate enough and comprehensive problem that becomes, the present invention proposes a kind of UUV self information and ocean current data fusion method, to obtain under earth coordinates accurate, complete ocean current profile information.

For obtain to continue, stable ocean current profile data, the present invention has designed the platform of an ADCP, be UUV, UUV mainly contains shell, thruster, DVL, ADCP, attitude sensor, compass, GPS and control computer and forms, UUV is certain depth when navigation under water, ADCP (transducer head is installed up or down) is under control computer control, and 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.

UUV carries ADCP and measures in the process of ocean current, because it is unreasonable that the self noise of instrument, sea situation factor, sonar installation deviation and parameter are provided with, and sensor errors such as attitude, compass, particularly when fish that motion is arranged in the water layer or sea life, make and contain abnormal data (wild value) and stochastic error in the ocean current observation data.The present invention carries out filtering to these raw data when the ocean current observation data is carried out aftertreatment, eliminate wild value, and random deviation of measurement is smoothly revised, and improves the precision of ocean current data.

Because sensors such as DVL, attitude sensor, compass are difficult to fully synchronously on sampling zero-time, sample frequency, transmission delay, the ocean current data that record, the speed of UUV and course data are asynchronous often before fusion.The synchrodata that the present invention inscribes when being identical with these asynchronous data reduction earlier before the ocean current observation data merges, this processing procedure just is called ocean current profile information time registration.

When UUV navigates by water under water, GPS can't receive real-time positional information, in order to obtain the UUV latitude and longitude information, need calculate estimation to the position of UUV, here the method that adopts the berth to calculate: UUV is since a known coordinate position, according to course, the speed of a ship or plane and the hours underway of UUV, calculate next coordinate position constantly at this point.

The ocean current profile data that the UUV underwater navigation obtains, do not comprise corresponding longitude and latitude positional information, accurate in order to obtain, comprehensive ocean current profile data, the present invention carries out data fusion with UUV longitude and latitude positional information and ocean current profile information: the longitude and latitude positional information of the berth being calculated gained converts ASCII character to, be inserted into the relevant position of ADCP packet, just finished the fusion of positional information and ocean current data after update package length and the check code.

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

The present invention can realize that ocean current profile and UUV positional information that ADCP that UUV carries obtains carry out data fusion, thereby obtains comprehensively, stable, reliable ocean current information.

Description of drawings

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

Fig. 2 is a UUV composition frame chart of the present invention;

Fig. 3 is that synoptic diagram is calculated in UUV of the present invention position;

Fig. 4 is an ocean current information time registration approach synoptic diagram of the present invention;

Fig. 5 is a fusion of the present invention back ocean current profile information WinRiver result.

Embodiment

The invention will be further described below in conjunction with accompanying drawing.

Accompanying drawing 2 is that UUV of the present invention system forms synoptic diagram, the 1st, thruster, the 2nd, DVL, the 3rd, ADCP, the 4th, attitude sensor, the 5th, compass, the 6th, control computer, the 7th, GPS, the 8th, UUV shell.

Fig. 3 is that principle schematic is calculated in the UUV position among the present invention, wherein initial longitude and latitude (J ₀, W ₀) be meant the GPS longitude and latitude that initial time was noted when carrying out the position calculated, (J, any time UUV position when W) calculating for the UUV position.

1. the ocean current profile data are obtained

By designing the ocean current profile information that a UUV (as shown in Figure 1) obtains the observation marine site, this UUV mainly contains shell, thruster, DVL, ADCP, attitude sensor, compass, GPS and control computer are formed, UUV is certain depth when navigation under water, ADCP (transducer head is installed up or down) is under control computer control, the sound wave of emission certain frequency, utilize Doppler effect can obtain the ocean current profile data of the certain water layer thickness in UUV top or bottom, the ocean current profile data are stored by the storage medium that serial ports (or network interface) is transferred to control computer, just can get access to the ocean current profile data by UUV like this.

2. ocean current observation data filtering

UUV carries ADCP and measures in the process of ocean current, because it is unreasonable that the self noise of instrument, sea situation factor, sonar installation deviation and parameter are provided with, and sensor errors such as attitude, compass, particularly when fish that motion is arranged in the water layer or sea life, make and contain abnormal data (wild value) and stochastic error in the ocean current observation data.Therefore, when the ocean current observation data is carried out aftertreatment, must carry out filtering, eliminate wild value, and random deviation of measurement is smoothly revised, improve the precision of ocean current data these raw data.

(1) based on the ocean current data unruly-value rejecting of fitting of a polynomial

Method of abnormal value removing and correction based on fitting of a polynomial need utilize the mean-square error criteria of three times of match residual sequences to differentiate rejecting, than other method easy operating to known polynomial expression of ocean current observation data match again.This method is as follows to ocean current observation data unruly-value rejecting step:

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:

$\mathrm{\σ}=\sqrt{\frac{{\mathrm{\Δy}}_1^2+{\mathrm{\Δy}}_2^2+\·+{\mathrm{\Δy}}_m^2}{m}}---\left(1\right)$

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 (2)

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 (3)

According to formula (2) and formula (3) as can be known, if residual values less than threshold value, is 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.Threshold value 3 σ can make suitable change according to the experiment concrete condition.

(2) based on the ocean current data smoothing of wavelet decomposition and reconstruct

Reject after the wild value, though the exceptional value in the data has not had, but because the ADCP that carries of UUV is subjected to the influence of scatterer and the various errors of internal system in the water in actual measurement, bring certain stochastic error to measurement data, especially the bigger situation of signal saltus step can appear in this non-stationary signal of ocean current data.Therefore, the subject matter that faces for the processing of Doppler measurement data is how to select a kind of active data smoothing method.Wavelet decomposition and reconfiguration technique are the very wide new data smoothing disposal routes of a kind of scope of application, has the detail section that when eliminating high frequency noise, keeps information, therefore the present invention adopts WAVELET PACKET DECOMPOSITION and signal reconstruction theory, and the ocean current data are carried out smoothly.Ocean current data smoothing based on wavelet decomposition and reconstruct is exactly that the many resolutions characteristics in the wavelet transformation of borrowing come data are decomposed, and by realized the decomposition successively to data by many resoluting signals algorithm of Mallat proposition, obtains the low-frequency information of original signal at last.

3. ocean current observation data temporal registration

Because sensors such as DVL, attitude sensor, compass are difficult to fully synchronously on sampling zero-time, sample frequency, transmission delay, the ocean current data that record, the speed of UUV and course data are asynchronous often before fusion.Therefore, the synchrodata of inscribing when before the fusion of ocean current observation data, needing elder generation to be identical with these asynchronous data reduction, this processing procedure just is called the temporal registration of ocean current profile information.

The present invention adopts the temporal registration scheme based on linear interpolation, the ultimate principle of linear interpolation is in the value that estimates on the high-precision observation data on the corresponding low precision time point, get three groups of observation datas in same processing cycle, utilize linear interpolation method, Time Created registration approach.Need three data sources of temporal registration by the ascending order of measuring accuracy to be: UUV speed data, UUV bow be to data, the current speed data, and detailed process is seen Fig. 4.

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, get final product following linear interpolation function:

4.UUV the reckoning of positional information

In UUV when navigation,, the speed that DVL records generally is the speed the hull coordinate system under, and the longitude and latitude of carrier when calculating that UUV navigates by water need be converted into speed under the east northeast coordinate system to the speed of UUV under the hull coordinate system.UUV carrier headway is calculated as follows at the component of due east direction and direct north:

$\left\{\begin{array}{c}{v}_E=v_F\sin H-v_L\cos H\\ v_N=v_F\cos H+v_L\sin H\end{array}\right.---\left(4\right)$

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 for just, for negative, can be recorded by compass clockwise counterclockwise.

In conjunction with Fig. 3, longitude and latitude can be calculated by formula (5) in the navigation of UUV carrier:

$\left\{\begin{array}{c}J=J_0+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{v}_{E,(i-1)}\mathrm{\Δt}/R_{M,(i-1)}\\ W=W_0+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{v}_{N,(i-1)}\mathrm{\Δt}/R_{N,(i-1)}\end{array}\right.---\left(5\right)$

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, can 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. the ocean current profile information data merges

Data fusion mainly is that UUV self information (attitude, course, navigation speed, position) and ocean current profile information are carried out other fusion of data level; Attitude with UUV, information translation such as course, navigation speed, position become ASCII character, through after preceding four step process, be fused to the relevant position in the ocean current profile information packet, just finished the fusion of positional information and ocean current data after update package length and the check code.Open ocean current profile packet after the fusion with ocean current the poster processing soft WinRiver software, just can obtain the size and Orientation of ocean current profile intuitively at arbitrary position ocean current profile.

Fig. 5 is the ADCP sensor that utilizes UUV of the present invention to carry, recorded certain regional ocean current profile information of observing when 7m navigates by water under water, utilize the result after the WinRiver software processes ocean current profile data fusion, the size and Orientation of the ocean current that from Fig. 5, can visually see.

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:

$\mathrm{\σ}=\sqrt{\frac{{\mathrm{\Δy}}_1^2+{\mathrm{\Δy}}_2^2+\·+{\mathrm{\Δy}}_m^2}{m}}$

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:

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

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:

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

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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