CN106054135A - Passive underwater sound positioning method based on moving time window periodically - Google Patents

Abstract

The present invention discloses a passive underwater sound positioning method based on moving a time window periodically. The method is composed of a strapdown inertial navigation system (SINS), a single hydrophone (receiver) at the bottom of an autonomous underwater vehicle (AUV) and a seafloor single hydrophone (band sound source), adopts a time window model which moves based on the cycle of an ultrasonic wave sent out by the seafloor hydrophone, and comprises the steps of carrying out the generalized cross correlation on the sound source signals received when the AUV is located at different positions in a time window to obtain the delay inequality, and then calculating a time window internal AUV multi-point model to obtain the latest position coordinate of the AUV. According to the present invention, by calculating the time window internal AUV multi-point model, the AUV does not need to navigate too far, so that a positioning error of an inertial navigation system which accumulates along with the time continuously is reduced effectively. According to the present invention, the AUV does not need to emerge from the water to update the position, does not need the digital communication, and receives an ultrasonic signal passively, so that the position of the AUV is difficult to expose, and the invisibility and the safety of the AUV are improved.

Description

A kind of passive underwater acoustic localization method based on cycle traveling time window

Technical field

The invention belongs to strap-down inertial technical field, particularly relate to as a kind of based on cycle traveling time window passive Hydrolocation method.

Background technology

AUV (Autonomous Underwater Vehicle, Autonomous Underwater Vehicle) is now various under water in execution Task plays an important role, including marine exploration, removes mines and collect the water-depth measurement number in ocean and river under water According to etc..In order to ensure that AUV can smoothly complete task under water, and obtain more accurate subaqueous survey data, be necessary for Require that it has long-term autonomous hi-Fix homing capability under water, and there is higher disguise.

Use DVL Yu SINS to be combined navigation in currently the majority AUV, and the method calculated by berth estimates position Put, but inertial navigation system position error so can be caused the most constantly to accumulate, and long-term autonomous high accuracy can not be met Positioning requirements.When AUV performs task in shallow sea, the navigation pattern of " submariner-water surface correction-submariner " of employing carries out location navigation, I.e. rely on SINS/DVL to carry out location navigation, in order to correct after AUV moves under water certain time under water when AUV navigates by water under water Cumulative error, AUV must go up floatation surface, uses SINS/GPS integrated navigation system to be corrected.Use this scheme, although energy Reach to correct the purpose of cumulative error, but be the necessity for AUV and constantly travel to and fro between underwater performance place and the water surface.Do so Not only affect work efficiency, and be easier to expose the position of AUV.Particularly when AUV is at deep-sea or under-ice work, this Scheme is more unrealistic.Therefore, a kind of the most long-term autonomous method carrying out reliable auxiliary positioning is studied the heaviest Want.

Summary of the invention

Goal of the invention: the present invention is directed to conventional DVL Yu SINS be combined position error that air navigation aid exists can be with Time of constantly accumulates, the navigation pattern of " submariner-water surface correction-submariner " position easily exposing AUV etc. is the most autonomous at AUV The problem that formula navigation aspect exists, it is provided that a kind of passive underwater acoustic localization method based on cycle traveling time window, utilizes seabed water Listen device to determine the position of carrier, the position coordinates calculated.It is particularly well-suited to long-term autonomous High precision underwater positioning lead Boat, and there is higher disguise.

Technical scheme: a kind of passive underwater acoustic localization method based on cycle traveling time window, comprises the following steps:

(1) the single hydrophone being fixed on seabed is positioned as sound source, calculate the position under its inertial coodinate system Coordinate P (x, y, z)；

(2) the hydrophone moment in seabed keeps duty, and constantly sends the ultrasonic pulse signal that the cycle is t, when After hydrophone fixing bottom AUV receives the pulse signal in 10 cycles as receptor, i.e. elapsed time 10t, AUV are Travel forward a segment distance, when hydrophone fixing bottom AUV receives the 11st pulse signal, determine and record AUV Current location P_i(i=0,1,2,3 ...), now occur that receptor connects as the original position of periodic signal using pulse signal Receive acoustical signal x in the cycle that seabed hydrophone sends_i(i=0,1,2,3 ...)；

(3) AUV is when hydrophone place Its Adjacent Waters navigates by water, when choosing the continuous position formation of 4 AUV recorded Between window, there is shown 4 position P_i(i=0,1,2,3) coordinate under absolute geographic coordinate system is:

$\begin{array}{c}(x_0,y_0,z_0)=\left(\right(x_3-{\mathrm{\Δx}}_1),(y_3-{\mathrm{\Δy}}_1),(z_3-{\mathrm{\Δz}}_1\left)\right)\\ (x_1,y_1,z_1)=\left(\right(x_3-{\mathrm{\Δx}}_2),(y_3-{\mathrm{\Δy}}_2),(z_3-{\mathrm{\Δz}}_2\left)\right)\\ (x_2,y_2,z_2)=\left(\right(x_3-{\mathrm{\Δx}}_3),(y_3-{\mathrm{\Δy}}_3),(z_3-{\mathrm{\Δz}}_3\left)\right)\\ (x_3,y_3,z_3)=(x_3,y_3,z_3)\end{array};$

(4) by P₃The acoustical signal that place receives respectively with P₂、P₁、P₀The acoustical signal that place receives is done cross-correlation and is obtained time delay Difference τ₃₂、τ₃₁、τ₃₀:

Δt_3i=τ_3i-(30-10i) t, (i=0,1,2)；

And AUV is at P_i(i=0,1,2,3) during place with seabed hydrophone P (x, y, distance z) is:

$L_i=\sqrt{{(x_i-x)}^2+{(y_i-y)}^2+{(z_i-z)}^2};$

So according to estimated delay inequality, the velocity of sound is set to steady state value under water, it is designated as c, obtains below equation group:

L₃-L₀=Δ t₃₀c

L₃-L₁=Δ t₃₁c；

L₃-L₂=Δ t₃₂c

(5) after substituting into equation group again after the range formula substituted into by the coordinate in step (3), by 3 sides in equation group Journey obtains required P₃Coordinate (x₃,y₃,z₃), i.e. the coordinate position that AUV is the most up-to-date.

The movement of the pulse signal cycle owing to sending with seabed hydrophone, with four continuous positions of AUV, formed multiple Time window, carries out identical calculations to time window afterwards, the position of AUV can be carried out real-time tracking and position, and uses the method After can obtain more accurate current position coordinates.

The method for expressing of described step (3) time window is:

1) position coordinates under the inertial coodinate system of original AUV is set as P₀(x₀,y₀,z₀), after elapsed time 10t, Obtain current position coordinates P₁(x₁,y₁,z₁), after elapsed time 20t, obtain current position coordinates P₂(x₂,y₂,z₂), After elapsed time 30t, obtain up-to-date position coordinates P₃(x₃,y₃,z₃), four points now form a time window；

2) pulse signal sent when seabed hydrophone is through 10 cycle i.e. 10t, and AUV obtains current inertial coordinate Position coordinates under Xi is P₄(x₄,y₄,z₄), now by P₀(x₀,y₀,z₀) delete from time window, and by current P₄With P₁、 P₂、P₃Form new time window.By that analogy, during AUV navigates by water, time window keeps the cycle of 10t to be moved rearwards by；

3) wherein in first time window, by the IMU on lash ship and compass sensor to course current for AUV, speed AUV x, y, z axle in absolute geographic coordinate system in 10t, 20t, 30t time measured etc. information and obtain after integral operation To distance to go be respectively Δ x₁、Δx₂、Δx₃、Δy₁、Δy₂、Δy₃、Δz₁、Δz₂、Δz₃, thus use latest position P₃ (x₃,y₃,z₃) it is unknown parameter, by P_i(i=0,1,2) it is expressed as:

(x₀,y₀,z₀)=((x₃-Δx₁),(y₃-Δy₁),(z₃-Δz₁))

(x₁,y₁,z₁)=((x₃-Δx₂),(y₃-Δy₂),(z₃-Δz₂))；

(x₂,y₂,z₂)=((x₃-Δx₃),(y₃-Δy₃),(z₃-Δz₃))

4) follow-up time window is identical with the processing method of first time window, joins as the unknown with the coordinate of latest position Number represents the coordinate of the position of first three record.

In described step (4), cross-correlation obtains the method for delay inequality and is:

5) assume that hydrophone is at P_iThe signal received is:

x_i(t)=α_ix(t-τ_i)+n_i(t)；

6) hydrophone is at P_jThe signal received is:

x_j(t)=α_jx(t-τ_j)+n_j(t)；

Wherein α_i、α_jFor acoustical signal at the attenuation quotient of water transmission, n_i(t)、n_jT () is orthogonal noise signal, τ_i、τ_jFor the propagation time；

7) by the formula of step (5), the hydrophone bottom AUV is done broad sense at the sound-source signal that diverse location receives mutual Correlation computations, x_i(t) and x_jT the cross-correlation function of () is:

$R_{x_i{x}_j}\left(\mathrm{\τ}\right)=E\[x_i\left(t\right){x^{*}}_j(t-\mathrm{\τ})\]=\frac{1}{T-\mathrm{\τ}}{\∫}_{\mathrm{\τ}}^T{x}_i\left(t\right)x_j(t-\mathrm{\τ})dt;$

8) wherein τ=τ_j-τ_i, represent that the time of advent is poor,_TRepresent observation time.According to the character of correlation function, as long as looking for Go outPeak value, the τ of its correspondence_ijBeing made up of two parts, one is that hydrophone fixing bottom AUV is at P_iPlace and P_jPlace due to From seabed hydrophone apart from the different time difference Δ t causing acoustic signal propagation time different and to cause_ij, two is that AUV is from P_jTo P_i Position through time kt (k be through periodicity).

Beneficial effect: the present invention by arranging single hydrophone (band sound source) at the bottom, and arranges single bottom AUV Hydrophone (receptor), utilizes seabed hydrophone persistently to send acoustical signal and the position of carrier is carried out real-time update, calculate Position coordinates be relative to the coordinate under terrestrial coordinate system, then by Coordinate Conversion, be converted into the longitude and latitude under earth coordinates Degrees of data.Present invention advantage compared with prior art is:

(1) present invention utilizes seabed hydrophone persistently to send acoustical signal to be determined the position of AUV, and AUV passively connects Second signal, is provided with higher disguise, it is not easy to expose the position of AUV.

(2) present invention uses the time window localization method moved based on the cycle, forms the time with four continuous positions of AUV Window, and cycle of pulse signal of sending according to seabed hydrophone of time window and move, the position of AUV can be carried out in real time with Track also positions, and can effectively reduce, after using the method, the position error that inertial navigation system is the most constantly accumulated, can obtain More accurate current position coordinates.

Accompanying drawing explanation

Fig. 1 is the flow chart of the present invention；

Fig. 2 is the time window model schematic block diagram of the present invention；

Fig. 3 is that sound-source signal of the present invention does broad sense cross-correlation and obtains delay inequality flow chart.

Detailed description of the invention

Below in conjunction with accompanying drawing, the case study on implementation of the present invention is described in detail；

Such as Fig. 1, the present invention to be embodied as step as follows:

1) first AUV gets hydrophone under water as band sound source position coordinates under inertial coodinate system by computer P(x,y,z)；

2) position coordinates under the inertial coodinate system of current AUV is then set as P₀(x₀,y₀,z₀), hereafter AUV is forward, and Moment keeps the ultrasound wave that receiving hydrophone sends, and after the ultrasound wave receiving 10 cycles, (i.e. navigates through the time 10t), AUV in-position P₁, AUV is by sensings such as the IMU (Inertial measurement unit) on lash ship and compass The information such as course current for AUV, speed are measured and after integral operation by device, the current x, y, z in inertial coodinate system of record Axial distance to go is respectively Δ x₁、Δy₁、Δz₁, and record the ultrasonic signal of next cycle, and after record end, AUV Continue sailed onward, after elapsed time 20t, AUV in-position P₂, record current in inertial coodinate system x, y, z axial Distance to go be respectively Δ x₂、Δy₂、Δz₂, and record the ultrasonic signal of next cycle, after elapsed time 30t, AUV in-position P₃, the current distance to go that x, y, z is axial in inertial coodinate system of record is respectively Δ x₃、Δy₃、Δz₃, and The ultrasonic signal of record next cycle；

3), when computer recording after four positions, computer, by the information of record, uses latest position P₃Inertia Coordinate (x under coordinate system₃,y₃,z₃) it is unknown parameter, can be by P_i(i=0,1,2) coordinate representation is:

(x₀,y₀,z₀)=((x₃-Δx₁),(y₃-Δy₁),(z₃-Δz₁))

(x₁,y₁,z₁)=((x₃-Δx₂),(y₃-Δy₂),(z₃-Δz₂))

(x₂,y₂,z₂)=((x₃-Δx₃),(y₃-Δy₃),(z₃-Δz₃))

1) computer is to P₃The acoustical signal that place receives respectively with P₂、P₁、P₀The acoustical signal that place receives does cross-correlation,

Such as Fig. 3, process is as follows:

Assume that hydrophone is at P_iThe signal received is (i=0,1,2,3):

x_i(t)=α_ix(t-τ_i)+n_i(t)；

Wherein α_iFor acoustical signal at the attenuation quotient of water transmission, n_iT () is orthogonal noise signal, τ_iFor

Propagation time；

Broad sense is done at the sound-source signal that diverse location receives mutual by the hydrophone bottom AUV in step (2)

Close and calculate, x_i(t) (i=0,1,2) and x₃T () cross-correlation function is:

$R_{x_i{x}_3}\left(\mathrm{\τ}\right)=E\[x_i\left(t\right){x^{*}}_3(t-\mathrm{\τ})\]=\frac{1}{T-\mathrm{\τ}}{\∫}_{\mathrm{\τ}}^T{x}_i\left(t\right)x_3(t-\mathrm{\τ})dt;$

Wherein τ=τ₃-τ_i, representing that the time of advent is poor, T represents observation time.Computer is found out by certain algorithm Peak value, the τ of its correspondence_i3Be made up of two parts, one be hydrophone fixing bottom AUV as receptor at P_iPlace and P₃Place by In from seabed hydrophone apart from the different time difference Δ t causing acoustic signal propagation time different and to cause_i3, two is that AUV is from P_iArrive P₃Position through time kt (k be through periodicity)；

So by P₃Place receives required time and the P of acoustical signal₂、P₁、P₀Place receive the required time of acoustical signal time Between difference be:

Δt_3i=τ_3i-(30-10i) t, (i=0,1,2)；

2) by AUV at P_i(i=0,1,2,3) during place with seabed hydrophone P (x, y, distance z) is:

$L_i=\sqrt{{(x_i-x)}^2+{(y_i-y)}^2+{(z_i-z)}^2};$

So the time difference obtained according to computer, the velocity of sound is set to steady state value under water, is designated as c, can obtain following side Journey group:

L₃-L₀=Δ t₃₀c

L₃-L₁=Δ t₃₁c；

L₃-L₂=Δ t₃₂c

3) after substituting into equation group again after the range formula that the coordinate in step (3) is substituted into by computer, by 3 in equation group Individual equation can obtain required P₃Coordinate (x₃,y₃,z₃), i.e. the coordinate position that AUV is the most up-to-date, then pass through Coordinate Conversion Becoming the longitude and latitude data under earth coordinates, now first time window has calculated；

4) AUV continues sailed onward, and the pulse signal that seabed hydrophone sends is again through 10 cycle i.e. 10t, and AUV arrives Reach position P₄, the current distance to go that x, y, z is axial in inertial coodinate system of record is respectively Δ x₂、Δy₂、Δz₂, and record The ultrasonic signal of next cycle, now by P₀(x₀,y₀,z₀) delete from time window, and by current P₄With P₁、P₂、P₃Group The time window of Cheng Xin.By that analogy, during AUV navigates by water, time window is always maintained at the cycle of 10t and is moved rearwards by；

5) time window hereafter is identical with the processing method of first time window, and the coordinate of available latest position is as the unknown Parameter list illustrates the coordinate of first three position recorded, thus obtains the exact value of the coordinate of latest position；

The present invention is directed to two kinds of situations of the prior art and propose effective settling mode: by strapdown inertial navigation system Single hydrophone (receptor) bottom SINS, AUV and seabed single hydrophone (band sound source) composition.Use based on seabed hydrophone Cycle of the ultrasound wave sent and the time window model of movement, receive time inside time window by AUV is in diverse location To sound-source signal do broad sense cross-correlation and obtain delay inequality, then to obtain AUV up-to-date by calculating the internal AUV Multiple point model of time window Position coordinates.Owing to time window constantly moved forward based on the ultrasound wave cycle, it is possible to reach preferable positioning precision and increase The redundancy of system.The present invention is calculated by the internal AUV Multiple point model of time window, and AUV distance to go is without too far, thus effectively Reduce inertial navigation system the most constantly to accumulate and the position error that causes.In the present invention AUV without on emerge and carry out Location updating, it is not necessary to data communication and AUV passively accept ultrasonic signal, are difficult to exposure position, improve AUV disguise and Safety.

Claims (3)

1. a passive underwater acoustic localization method based on cycle traveling time window, it is characterised in that comprise the following steps:

(1) the single hydrophone being fixed on seabed is positioned as sound source, calculate the position coordinates P under its inertial coodinate system (x,y,z)；

(2) the hydrophone moment in seabed keeps duty, and constantly sends the ultrasonic pulse signal that the cycle is t, when at the bottom of AUV After the hydrophone that portion is fixed receives the pulse signal in 10 cycles as receptor, i.e. elapsed time 10t, AUV are the most forward Travel a segment distance, when hydrophone fixing bottom AUV receives the 11st pulse signal, determine and record that AUV is current Position P_i(i=0,1,2,3 ...), now using the original position as periodic signal that occurs of pulse signal, receptor reception sea Acoustical signal x in the cycle that end hydrophone sends_i(i=0,1,2,3 ...)；

(3) AUV is when hydrophone place Its Adjacent Waters navigates by water, and the continuous position choosing 4 AUV recorded forms the time Window, there is shown 4 position P_i(i=0,1,2,3) coordinate under absolute geographic coordinate system is:

$\begin{array}{c}(x_0,y_0,z_0)=\left(\right(x_3-{\mathrm{\Δx}}_1),(y_3-{\mathrm{\Δy}}_1),(z_3-{\mathrm{\Δz}}_1\left)\right)\\ (x_1,y_1,z_1)=\left(\right(x_3-{\mathrm{\Δx}}_2),(y_3-{\mathrm{\Δy}}_2),(z_3-{\mathrm{\Δz}}_2\left)\right)\\ (x_2,y_2,z_2)=\left(\right(x_3-{\mathrm{\Δx}}_3),(y_3-{\mathrm{\Δy}}_3),(z_3-{\mathrm{\Δz}}_3\left)\right)\\ (x_3,y_3,z_3)=(x_3,y_3,z_3)\end{array};$

(4) by P₃The acoustical signal that place receives respectively with P₂、P₁、P₀The acoustical signal that place receives is done cross-correlation and is obtained delay inequality τ₃₂、 τ₃₁、τ₃₀:

Δt_3i=τ_3i-(30-10i) t, (i=0,1,2)；

And AUV is at P_i(i=0,1,2,3) during place with seabed hydrophone P (x, y, distance z) is:

$L_i=\sqrt{{(x_i-x)}^2+{(y_i-y)}^2+{(z_i-z)}^2};$

So according to estimated delay inequality, the velocity of sound is set to steady state value under water, it is designated as c, obtains below equation group:

$\begin{array}{c}{L}_3-L_0={\mathrm{\Δt}}_{30}c\\ L_3-L_1={\mathrm{\Δt}}_{31}c\\ L_3-L_2={\mathrm{\Δt}}_{32}c\end{array};$

(5) after substituting into equation group again after the range formula substituted into by the coordinate in step (3), 3 equations in equation group obtain To required P₃Coordinate (x₃,y₃,z₃), i.e. the coordinate position that AUV is the most up-to-date.

A kind of passive underwater acoustic localization method based on cycle traveling time window the most according to claim 1, it is characterised in that The method for expressing of described step (3) time window is:

1) position coordinates under the inertial coodinate system of original AUV is set as P₀(x₀,y₀,z₀), after elapsed time 10t, obtain Current position coordinates P₁(x₁,y₁,z₁), after elapsed time 20t, obtain current position coordinates P₂(x₂,y₂,z₂), at warp After crossing time 30t, obtain up-to-date position coordinates P₃(x₃,y₃,z₃), four points now form a time window；

2) pulse signal sent when seabed hydrophone is through 10 cycle i.e. 10t, and AUV obtains under current inertial coodinate system Position coordinates be P₄(x₄,y₄,z₄), now by P₀(x₀,y₀,z₀) delete from time window, and by current P₄With P₁、P₂、P₃ Form new time window.By that analogy, during AUV navigates by water, time window keeps the cycle of 10t to be moved rearwards by；

3), wherein in first time window, by the IMU on lash ship and compass sensor, course current for AUV, speed etc. are believed In ceasing 10t, 20t, 30t time measuring and obtaining after integral operation, AUV x, y, z in absolute geographic coordinate system is axial Distance to go is respectively Δ x₁、Δx₂、Δx₃、Δy₁、Δy₂、Δy₃、Δz₁、Δz₂、Δz₃, thus use latest position P₃(x₃, y₃,z₃) it is unknown parameter, by P_i(i=0,1,2) it is expressed as:

$\begin{array}{c}(x_0,y_0,z_0)=\left(\right(x_3-{\mathrm{\Δx}}_1),(y_3-{\mathrm{\Δy}}_1),(z_3-{\mathrm{\Δz}}_1\left)\right)\\ (x_1,y_1,z_1)=\left(\right(x_3-{\mathrm{\Δx}}_2),(y_3-{\mathrm{\Δy}}_2),(z_3-{\mathrm{\Δz}}_2\left)\right)\\ (x_2,y_2,z_2)=\left(\right(x_3-{\mathrm{\Δx}}_3),(y_3-{\mathrm{\Δy}}_3),(z_3-{\mathrm{\Δz}}_3\left)\right)\end{array};$

4) follow-up time window is identical with the processing method of first time window, with the coordinate of latest position as unknown parameter table The coordinate of first three position recorded is shown.

A kind of passive underwater acoustic localization method based on cycle traveling time window the most according to claim 1, it is characterised in that In described step (4), cross-correlation obtains the method for delay inequality and is:

5) assume that hydrophone is at P_iThe signal received is:

x_i(t)=α_ix(t-τ_i)+n_i(t)；6) hydrophone is at P_jThe signal received is:

x_j(t)=α_jx(t-τ_j)+n_j(t)；

Wherein α_i、α_jFor acoustical signal at the attenuation quotient of water transmission, n_i(t)、n_jT () is orthogonal noise signal, τ_i、τ_j For the propagation time；

7) by the formula of step (5), the hydrophone bottom AUV is done broad sense cross-correlation at the sound-source signal that diverse location receives Calculate, x_i(t) and x_jT the cross-correlation function of () is:

$R_{x_i{x}_j}\left(\mathrm{\τ}\right)=E\[x_i\left(t\right){x^{*}}_j(t-\mathrm{\τ})\]=\frac{1}{T-\mathrm{\τ}}{\∫}_{\mathrm{\τ}}^T{x}_i\left(t\right)x_j(t-\mathrm{\τ})dt;$

8) wherein τ=τ_j-τ_i, representing that the time of advent is poor, T represents observation time.According to the character of correlation function, as long as finding outPeak value, the τ of its correspondence_ijBeing made up of two parts, one is that hydrophone fixing bottom AUV is at P_iPlace and P_jPlace due to The different time difference Δ t causing acoustic signal propagation time different and to cause of seabed hydrophone distance_ij, two is that AUV is from P_jTo P_iPosition Put through time kt (k be through periodicity).