阅读说明：本技术 基于圆柱阵的自主阵形规划水声定位方法和系统 (Autonomous formation planning underwater acoustic positioning method and system based on cylindrical array ) 是由 何桂萍 樊勇 陈洲 王正伟 于 2020-06-04 设计创作，主要内容包括：本发明公开了基于圆柱阵的自主阵形规划水声定位方法和系统,涉及水声定位领域,解决了传统固定阵元阵形进行定位,空间不同分布区域定位精度差异较大,导致部分区域定位效果不理想或不能进行定位的问题。本发明根据当前圆柱阵形各阵元的相对位置,选定其中某几个阵元,构建一个定位阵形并进行定位解算,在局部区域内取得最优定位结果,实现了小平台下基于TDOA和最优定位阵形选择的全方位高精度水声被动目标定位技术。具有模型简洁易用、结果准确可靠等特点,可实用、高效、高精度地对水下各个方向目标进行实时可靠定位。(The invention discloses an autonomous array planning underwater acoustic positioning method and system based on a cylindrical array, relates to the field of underwater acoustic positioning, and solves the problems that the positioning effect of partial areas is not ideal or the positioning cannot be carried out due to the fact that the positioning accuracy difference of different spatial distribution areas is large when the traditional fixed array element array is used for positioning. According to the invention, according to the relative position of each array element of the current cylindrical array, a certain number of array elements are selected, a positioning array is constructed and positioning calculation is carried out, an optimal positioning result is obtained in a local area, and the omnibearing high-precision underwater sound passive target positioning technology based on TDOA and optimal positioning array selection under a small platform is realized. The method has the characteristics of simple and easy model, accurate and reliable result and the like, and can be used for reliably positioning underwater targets in all directions in real time in a practical, efficient and high-precision manner.)

1. An autonomous formation planning underwater acoustic positioning method based on a cylindrical array is characterized by comprising the following steps:

s1: establishing a positioning equation by utilizing the time difference between a target to be positioned and the underwater acoustic array element array, searching a primary position estimation by adopting a full-water-area target, detecting a radiation source signal of the same target to be positioned by adopting a Y-shaped array form selected by the full-water-area target searching primary position estimation, and expressing the array elements of the radiation source signal by adopting a set;

s2: and adopting target accurate position estimation, selecting a T-shaped positioning auxiliary array element by utilizing a Y-shaped array positioning result in S1, applying a time difference positioning method, selecting a positioning auxiliary array element based on a template matching method and a minimum azimuth angle difference, selecting a deblurring auxiliary array element based on the minimum azimuth angle difference, and simultaneously obtaining the accurate position estimation of the target by utilizing a TDOA time difference positioning method.

2. The method for autonomous underwater acoustic positioning based on cylindrical array planning as claimed in claim 1, wherein said S1 further comprises selecting a main positioning array element, selecting a sub positioning array element based on template matching and least square, selecting a deblurring sub array element based on minimum azimuth angle difference, TDOA time difference positioning, and the concrete steps of:

s11: the array element set for obtaining the radiation source signal is expressed as:

radiation source signal i ═ S_i＝{A_j}，i∈[1,M]，j∈[1,Num]

Wherein M represents the number of detected signals, A_jThe number of the detection array elements is represented, Num is less than or equal to the total number of the detection array elements, S is a set formed by some detection array elements, wherein each element in S detects all signals, and the set can be represented as follows:

S＝S₁∩S₂∩...∩S_Mthe element is a detection array element;

selecting main array elements:

selecting the geometric center (x) of each detection array element_c,y_c,z_c) The most recent array element is the main array element, and the algorithm formula is as follows:

s12: selecting a secondary array element based on a template matching method and a least square method:

s121: calculating each detecting array element to positioning main array element (x)₀,y₀,z₀) A distance r of_i(i＝1,2,...,Num-1)：

Wherein r is_iThe detection array element point set with the length more than or equal to the required base line length is recorded as a set S (x)_i,y_i,z_i)，i∈[0,Num1](Num1 is less than or equal to the total number of the detection array elements);

s122: and (3) coordinate conversion:

to locate the main array element x₀,y₀,z₀Taking the east as an X axis, the north as a Y axis and the Z axis as a positive direction perpendicular to the XY plane as a coordinate origin, and establishing a space rectangular coordinate system;

converting the set S into a space rectangular coordinate system, projecting the set S to an XY plane, and recording the XY plane as S_xy(x_i,y_i) And then S is_xy(x_i,y_i) Conversion to polar S_rθ(r_i,θ_i)；

S123: selecting a positioning pair array element based on a template matching method and a least square method:

selecting azimuth angles of OA, OB and OC which are respectively 0 degrees, 120 degrees and 240 degrees, and forming a Y-shaped array template by the OA, OB and OC;

rotating the Y-shaped array by 120 degrees along the anticlockwise direction, stepping by 1 degree, and respectively calculating a set S of the Y-shaped array at different rotation angles_rθ(r_i,θ_i) The sum of the squares of the differences in azimuth angles with OA, OB, and OC, i.e.:

wherein j represents a rotation angle of the Y-shaped array, and θ_OA(j)、θ_OB(j)、θ_OC(j) Respectively showing the azimuth angles of OA, OB and OC at different rotation angles of the Y-shaped array;

selecting min (. DELTA.)_azimuth(j) Corresponding 3 sub-array elements are positioning sub-array elements;

s124: and (3) deblurring auxiliary array element selection based on the minimum azimuth angle difference:

selecting 3 positioning auxiliary array elements respectively positioned at A₁、B₁、C₁Point, respectively calculate the angle A₁OB₁、B₁OC₁、A₁OC₁Azimuth angle of the center line, respectivelyAnd

in the set S_rθ(r_i,θ_i) Deletion in A₁、B₁、C₁Point, is denoted as S_AM(r_i,θ_i) Separately computing the set S_AM(r_i,θ_i) And andthe square of the difference, i.e.:

selecting min (. DELTA.)_θAB1(i),Δ_θBC1(i),Δ_θAC1(i) ) selecting corresponding array elements as deblurring auxiliary array elements;

s125: calculating TDOA between each secondary array element and the main positioning array element, and realizing preliminary position estimation (x) of full-water-area target search by applying TDOA positioning_Yi,y_Yi,z_Yi)。

3. The method for planning underwater acoustic positioning based on the autonomous formation of the cylindrical array of claim 2, wherein the step S2 further comprises the following steps:

s21: construction of standard T-shaped formation template

And projecting the target i to an XY plane, and calculating the azimuth angle of M by assuming the projection point to be M. Constructing a standard T-shaped array template A by taking a connecting line OM of main array elements O and M as a reference₁OB₁C₁Respectively calculate OA₁、OB₁、OC₁The azimuth of (d);

s22: positioning pair array element selection based on minimum azimuth angle difference

Separately calculate the set S_rθ(r_i,θ_i) And OA₁、OB₁、OC₁And selecting 3 receiving array elements with the minimum azimuth difference as T-shaped positioning auxiliary array elements according to the square of the azimuth difference, namely:

s23: deblurring auxiliary array element selection based on minimum azimuth angle difference

Azimuth angle theta of OM_MAs a basis, a set S is calculated_rθ(r_i,θ_i) And theta_MThe difference between:

selecting the receiving array element with the minimum azimuth angle difference as a deblurring auxiliary array element;

s24: calculating TDOA between each secondary array element and the main positioning array element, and realizing accurate position estimation (x) of underwater target by using TDOA positioning_Ti,y_Ti,z_Ti)。

4. An autonomous formation planning underwater acoustic positioning system based on a cylindrical array, characterized in that the system executes the autonomous formation planning underwater acoustic positioning method based on a cylindrical array as claimed in claim 1.

5. The system for autonomous formation planning underwater acoustic positioning based on cylindrical arrays according to claim 4, wherein the system performs S1 including selecting a main positioning array element, selecting a secondary positioning array element based on template matching and least square method, selecting a deblurred secondary array element based on minimum azimuth angle difference, and TDOA moveout location operation;

the array element set for obtaining the radiation source signal is expressed as:

radiation source signal i ═ S_i＝{A_j}，i∈[1,M]，j∈[1,Num]

Wherein M represents the number of detected signals, A_jThe number of the detection array elements is represented, Num is less than or equal to the total number of the detection array elements, S is a set formed by some detection array elements, wherein each element in S detects all signals, and the set can be represented as follows:

S＝S₁∩S₂∩...∩S_Mthe element is a detection array element;

selecting main array elements:

selecting the geometric center (x) of each detection array element_c,y_c,z_c) The most recent array element is the main array element, and the algorithm formula is as follows:

the system selects the auxiliary array elements based on a template matching method and a least square method:

the system calculates the position of each detecting array element to the main positioning array element (x)₀,y₀,z₀) A distance r of_i(i＝1,2,...,Num-1)：

Wherein r is_iThe detection array element point set with the length more than or equal to the required base line length is recorded as a set S (x)_i,y_i,z_i)，i∈[0,Num1](Num1 is less than or equal to the total number of the detection array elements);

the system performs coordinate transformation:

to locate the main array element x₀,y₀,z₀Taking the east as an X axis, the north as a Y axis and the Z axis as a positive direction perpendicular to the XY plane as a coordinate origin, and establishing a space rectangular coordinate system;

converting the set S into a space rectangular coordinate system, projecting the set S to an XY plane, and recording the XY plane as S_xy(x_i,y_i) And then S is_xy(x_i,y_i) Conversion to polar S_rθ(r_i,θ_i)；

The system selects the positioning pair array elements based on a template matching method and a least square method:

selecting azimuth angles of OA, OB and OC which are respectively 0 degrees, 120 degrees and 240 degrees, and forming a Y-shaped array template by the OA, OB and OC;

rotating the Y-shaped array by 120 degrees along the anticlockwise direction, stepping by 1 degree, and respectively calculating a set S of the Y-shaped array at different rotation angles_rθ(r_i,θ_i) The sum of the squares of the differences in azimuth angles with OA, OB, and OC, i.e.:

wherein j represents a rotation angle of the Y-shaped array, and θ_OA(j)、θ_OB(j)、θ_OC(j) Respectively showing the azimuth angles of OA, OB and OC at different rotation angles of the Y-shaped array;

selecting min (. DELTA.)_azimuth(j) Corresponding 3 sub-array elements are positioning sub-array elements;

the system performs deblurring auxiliary array element selection based on the minimum azimuth angle difference:

selecting 3 positioning auxiliary array elements respectively positioned at A₁、B₁、C₁Point, respectively calculate the angle A₁OB₁、B₁OC₁、A₁OC₁Azimuth angle of the center line, respectivelyAnd

in the set S_rθ(r_i,θ_i) Deletion in A₁、B₁、C₁Point, is denoted as S_AM(r_i,θ_i) Separately computing the set S_AM(r_i,θ_i) And andthe square of the difference, i.e.:

selecting min (. DELTA.)_θAB1(i),Δ_θBC1(i),Δ_θAC1(i) ) corresponding array elements are selected as deblurred sub-array elements；

The system calculates TDOA between each secondary array element and the positioning main array element, and realizes the initial position estimation (x) of the full-water-area target search by applying the TDOA positioning_Yi,y_Yi,z_Yi)。

6. The cylindrical array based autonomous formation planning underwater acoustic positioning system of claim 5, wherein the system constructs a standard T-shaped formation template;

and projecting the target i to an XY plane, and calculating the azimuth angle of M by assuming the projection point to be M. Constructing a standard T-shaped array template A by taking a connecting line OM of main array elements O and M as a reference₁OB₁C₁Respectively calculate OA₁、OB₁、OC₁The azimuth of (d);

the system selects the positioning auxiliary array elements based on the minimum azimuth angle difference;

the system calculates sets S separately_rθ(r_i,θ_i) And OA₁、OB₁、OC₁And selecting 3 receiving array elements with the minimum azimuth difference as T-shaped positioning auxiliary array elements according to the square of the azimuth difference, namely:

the system performs deblurring auxiliary array element selection based on the minimum azimuth angle difference:

azimuth angle theta of OM_MAs a basis, a set S is calculated_rθ(r_i,θ_i) And theta_MThe difference between:

selecting the receiving array element with the minimum azimuth angle difference as a deblurring auxiliary array element;

the system calculates TDOA between each secondary array element and the main positioning array element, and realizes accurate position estimation (x) of the underwater target by using the TDOA_Ti,y_Ti,z_Ti)。

Technical Field

The invention relates to an underwater acoustic positioning technology, in particular to an autonomous formation planning underwater acoustic positioning method and system based on a cylindrical array.

Background

The underwater acoustic positioning is mainly aimed at positioning ships, submarines, underwater equipment and underwater organisms, the positioning principle is mainly that the existing positioning estimation method is used for positioning in an underwater environment, a positioning equation is established by using time difference or angle difference between a target to be positioned and an underwater acoustic array element array, the positioning equation is solved according to geometric position coordinates of the array element array, and finally the relative coordinates of the target position are obtained to complete the underwater acoustic positioning.

The common positioning method comprises time delay difference positioning and phase difference positioning, wherein both methods establish a positioning equation by utilizing time difference and angle difference between a target to be positioned and an underwater acoustic array element array, solve the positioning equation according to the geometric position coordinates of the array element array, and finally obtain the relative coordinates of the target position to complete the underwater acoustic positioning.

The requirement of passive positioning determines the arrangement mode of the underwater acoustic sensors in the system to be very important. The reasonable selection of the formation planning can not only improve the precision of the positioning algorithm, but also increase the coverage field of the positioning system, and can compensate the error caused by the time delay estimation calculation method to a certain extent. In underwater environment, the arrangement mode can be divided into linear array, area array and three-dimensional array according to the difference of the geometrical shapes. The coverage area of the linear array can only be one-dimensional space and the positioning space is fuzzy, so the method is less used in practical application; the coverage area of the area array is a two-dimensional space, and two-dimensional positioning can be carried out on targets in the upper half space and the lower half space of the plane of the area array; the coverage field of the three-dimensional array is the whole three-dimensional space, and the targets in the coverage range of the three-dimensional array can be positioned.

The positioning accuracy of the passive positioning system is related to parameters such as hydrophone array element spacing, array arrangement form, target space area distribution and the like. The traditional method adopts a fixed array element array form to position, so that the positioning precision difference of different spatial distribution areas is large, and the situation that positioning cannot be carried out in some areas can occur, so that the positioning effect is not ideal or the positioning cannot be carried out.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the positioning accuracy of the passive positioning system is related to parameters such as hydrophone array element spacing, array form, target space area distribution and the like. The traditional method adopts a fixed array element array form to carry out positioning, so that the positioning precision difference of different distribution areas in space is large, the situation that the positioning cannot be carried out can occur in some areas, and the positioning effect is not ideal or the positioning cannot be carried out.

The invention provides an autonomous array planning underwater acoustic positioning method and system based on a cylindrical array, which solve the problems, and array autonomous planning is carried out on array elements in the cylindrical array through a certain algorithm so as to achieve the purpose of high-precision positioning of all-round targets in a certain range.

The invention is realized by the following technical scheme:

s1: establishing a positioning equation by utilizing the time difference between a target to be positioned and the underwater acoustic array element array, searching a primary position estimation by adopting a full-water-area target, searching a Y-shaped array form selected by the primary position estimation by the full-water-area target, detecting a radiation source signal of the same target to be positioned, and expressing the array elements of the radiation source signal by adopting a set;

further, S1 further includes selecting a main location array element, selecting a sub location array element based on a template matching method and a least square method, selecting a deblurring sub array element based on a minimum azimuth difference, and TDOA time difference location, and the specific steps are as follows:

s11: the array element set for obtaining the radiation source signal is expressed as:

radiation source signal i ═ S_i＝{A_j}，i∈[1,M]，j∈[1,Num]

Wherein M represents the number of detected signals, A_jThe number of the detection array elements is represented, Num is less than or equal to the total number of the detection array elements, S is a set formed by some detection array elements, wherein each element in S detects all signals, and the set can be represented as follows:

S＝S₁∩S₂∩...∩S_Mthe element is a detection array element;

selecting main array elements:

selecting the geometric center (x) of each detection array element_c,y_c,z_c) The most recent array element is the main array element, and the algorithm formula is as follows:

s12: selecting a secondary array element based on a template matching method and a least square method:

s121: calculating each detecting array element to positioning main array element (x)₀,y₀,z₀) A distance r of_i(i＝1,2,...,Num-1)：

Wherein r is_iThe detection array element point set with the length more than or equal to the required base line length is recorded as a set S (x)_i,y_i,z_i)，i∈[0,Num1](Num1 is less than or equal to the total number of the detection array elements);

s122: and (3) coordinate conversion:

to locate the main array element x₀,y₀,z₀Taking the east as an X axis, the north as a Y axis and the Z axis as a positive direction perpendicular to the XY plane as a coordinate origin, and establishing a space rectangular coordinate system;

converting the set S into a space rectangular coordinate system, projecting the set S to an XY plane, and recording the XY plane as S_xy(x_i,y_i) And then S is_xy(x_i,y_i) Conversion to polar S_rθ(r_i,θ_i)；

S123: selecting a positioning pair array element based on a template matching method and a least square method:

selecting azimuth angles of OA, OB and OC which are respectively 0 degrees, 120 degrees and 240 degrees, and forming a Y-shaped array template by the OA, OB and OC;

rotating the Y-shaped array by 120 degrees along the anticlockwise direction, stepping by 1 degree, and respectively calculating a set S of the Y-shaped array at different rotation angles_rθ(r_i,θ_i) The sum of the squares of the differences in azimuth angles with OA, OB, and OC, i.e.:

wherein j represents a rotation angle of the Y-shaped array, and θ_OA(j)、θ_OB(j)、θ_OC(j) Respectively showing the azimuth angles of OA, OB and OC at different rotation angles of the Y-shaped array;

selecting min (. DELTA.)_azimuth(j) Corresponding 3 sub-array elements are positioning sub-array elements;

s124: and (3) deblurring auxiliary array element selection based on the minimum azimuth angle difference:

selecting 3 positioning auxiliary array elements respectively positioned at A₁、B₁、C₁Point, respectively calculate the angle A₁OB₁、B₁OC₁、A₁OC₁The azimuth angles of the center lines are respectively recorded asAnd

in the set S_rθ(r_i,θ_i) Deletion in A₁、B₁、C₁Point, is denoted as S_AM(r_i,θ_i) Separately computing the set S_AM(r_i,θ_i) And andthe square of the difference, i.e.:

selecting min (. DELTA.)_θAB1(i),Δ_θBC1(i),Δ_θAC1(i) ) selecting corresponding array elements as deblurring auxiliary array elements;

s125: calculating TDOA between each secondary array element and the main positioning array element, and realizing full-water-area target search initial position estimation (x) by applying TDOA positioning_Yi,y_Yi,z_Yi)。

S2: and adopting target accurate position estimation, selecting a T-shaped positioning auxiliary array element by utilizing a Y-shaped array positioning result in S1, applying a time difference positioning method, selecting a positioning auxiliary array element based on a template matching method and a minimum azimuth angle difference, selecting a deblurring auxiliary array element based on the minimum azimuth angle difference, and simultaneously obtaining the accurate position estimation of the target by utilizing a TDOA time difference positioning method.

Further, the S2 further includes the following specific steps:

s21: construction of standard T-shaped formation template

And projecting the target i to an XY plane, and calculating the azimuth angle of M by assuming the projection point to be M. Constructing a standard T-shaped array template A by taking a connecting line OM of main array elements O and M as a reference₁OB₁C₁Respectively calculate OA₁、OB₁、OC₁The azimuth of (d);

s22: positioning pair array element selection based on minimum azimuth angle difference

Separately calculate the set S_rθ(r_i,θ_i) And OA₁、OB₁、OC₁And selecting 3 receiving array elements with the minimum azimuth difference as T-shaped positioning auxiliary array elements according to the square of the azimuth difference, namely:

s23: deblurring auxiliary array element selection based on minimum azimuth angle difference

Azimuth angle theta of OM_MAs a basis, a set S is calculated_rθ(r_i,θ_i) And theta_MThe difference between:

selecting the receiving array element with the minimum azimuth angle difference as a deblurring auxiliary array element;

s24: calculating TDOA between each secondary array element and the main positioning array element, and realizing accurate position estimation (x) of underwater target by using TDOA positioning_Ti,y_Ti,z_Ti)。

An autonomous formation planning underwater acoustic positioning system based on a cylindrical array, said system performing any of the method steps of the above method.

The invention has the following advantages and beneficial effects:

the invention can be widely applied to real-time position monitoring and tracking of underwater targets in all directions, is passive and passive positioning, can position the target position without transmitting a detection signal by a terminal, and can covertly determine the position of a source target by receiving an acoustic signal, an electromagnetic wave signal and the like sent by the target by the positioning terminal.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

fig. 1 shows the cylindrical solid array topology of the present invention.

Fig. 2 shows the layout scheme of the array elements of the present invention.

FIG. 3 is a schematic diagram of the distribution of GDOP errors in the Y-shaped array element array of the present invention.

FIG. 4 is a schematic diagram of GDOP error distribution of the T-shaped array element array of the present invention.

FIG. 5 is a diagram of the distribution of GDOP errors in the form of a diamond array element according to the present invention.

FIG. 6 is a diagram of the distribution of GDOP errors in the array of parallelogram array elements according to the present invention.

FIG. 7 is a graph of the relative error of target positioning in different orientations in accordance with the present invention.

FIG. 8 is a flow chart of the initial position estimation for full-scale target search according to the present invention.

Fig. 9 is a coordinate transformation diagram of the present invention.

FIG. 10 is a diagram of the present invention for selecting deblurring sub-array elements based on minimum azimuth angle difference.

FIG. 11 is a flow chart of the precise location estimation of an underwater target of the present invention.

Fig. 12 is a diagram of the selection of the sub-array elements based on the template matching method and the minimum azimuth difference according to the present invention.

Detailed Description

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. All other embodiments, which can be obtained by a person skilled in the art without making inventive modifications based on the embodiments of the present invention, are within the scope of the present invention.

Firstly, the invention researches an omnibearing high-precision underwater sound positioning technology based on the autonomous planning of a cylindrical array positioning formation. According to the relative position of each array element of the current cylindrical array, a certain number of array elements are selected by a certain mechanism, a positioning array is constructed and is positioned and resolved, the optimal positioning result is obtained in a local area, the problem that the traditional fixed array element array is positioned, the positioning accuracy difference of different spatial distribution areas is large, the problem that the positioning effect of partial areas is unsatisfactory or the positioning cannot be carried out is caused, and the omnibearing high-precision underwater sound passive target positioning technology based on TDOA and optimal positioning array selection under a small platform is realized. The underwater target positioning method has the characteristics of simple and clean model, accurate and reliable result and the like, and can be used for reliably positioning underwater targets in all directions in real time in a practical, efficient and high-precision manner.

Wherein, the cylinder battle array structure:

the cylindrical three-dimensional array matrix form is shown in figure 1 and belongs to a foldable expansion array. The three-dimensional array consists of 12 expansion arms, wherein the 12 expansion arms are uniformly distributed on the circumference, the three-dimensional array can be decomposed into a vertical linear array and a horizontal circular array, and the 12 vertical linear arrays cover 360-degree vertical water area signal detection and reception; the horizontal circular array is responsible for detecting and receiving signals of 360-degree horizontal water areas.

Omnibearing high-precision underwater sound positioning method based on positioning formation autonomous planning

The invention adopts TDOA time difference location, and by the TDOA location principle, the location precision is related to the geometric distribution of array elements and a target radiation source, and the method mainly comprises the following steps:

the longer the mutual distance between the array elements is, the higher the positioning precision is;

the farther the distance between the target radiation source and the array element is, the lower the positioning precision is;

the relative positions of the array elements, namely the array shapes are different, the array elements have the shapes of equal-precision lines with different shapes, and under a certain array distribution type, targets in different directions on the same distance ring have different positioning precision.

According to the relative position of each array element of the current cylindrical three-dimensional array, a certain array element is selected by a template matching method, a positioning array is constructed and positioning calculation is carried out, an optimal positioning result is obtained in a local area, and the omnibearing high-precision passive target positioning technology based on TDOA and optimal positioning array selection under an underwater small platform is realized.

According to the spatial distribution of four array elements, the layout schemes can be roughly divided into Y-shaped, T-shaped, rhombic and parallelogram array element layout schemes, as shown in FIG. 2.

It can be seen from the simulation diagrams (fig. 3-6) of the positioning accuracy of different array element layout schemes: the positioning accuracy of different arrays is different, the positioning accuracy of the Y-shaped array is approximately and uniformly distributed in all directions, and the method is suitable for the omnibearing target search position estimation; when the target is positioned near the y axis, the method is suitable for searching and positioning the diamond or T-shaped target radiation source; the target radiation source has the highest positioning precision in the directions of 45 degrees of the x axis and the y axis due to the parallelogram array.

The Y-shaped array and the T-shaped array have simple structures, low complexity of array planning and highest positioning precision of the positive direction of the Y axis of the T-shaped array, and the Y-shaped array and the T-shaped array are adopted to realize the omnibearing high-precision positioning of the underwater target. For the Y-shaped and T-shaped arrays, the relative error map of the target phase in different directions is shown in FIG. 7, and it can be seen from the map that when the azimuth angle of the target radiation source is approximately within the range of [60 °,120 ° ], the positioning accuracy of the T-shaped array is higher than that of the Y-shaped array, and when the azimuth angle is 90 °, the positioning accuracy of the T-shaped array is the highest.

Preferably, the method adopts twice formation planning of full-water-area target search preliminary position estimation and target accurate position estimation to realize rapid and accurate positioning of the target. When the target position is uncertain, carrying out initial position estimation of the target search in the whole water area by adopting a Y-shaped array with uniformly distributed errors in all directions; and primarily estimating the distance and the direction of the target by utilizing the Y-shaped positioning result, and selecting the positive direction of the Y axis of the T-shaped array to carry out accurate position estimation on the target through autonomous array planning to obtain accurate position information of the target radiation source. And array element nodes with large array element intervals are selected as much as possible in the positioning process.

The autonomous formation planning underwater acoustic positioning method based on the cylindrical array comprises the following steps:

s1: the initial position estimation of the full-water-area target search selects a Y-shaped array to estimate the position of the target radiation source. The array elements representing the detection of the same target radiation source signal, i.e.

Radiation source signal i ═ S_i＝{A_j}，i∈[1,M]，j∈[1,Num]

Wherein M represents the number of detected signals, A_jThe number of the detection array elements is shown, and Num is less than or equal to the total number of the detection array elements.

Defining a set S, S being a set of several detection array elements, where every element (detection array element) in S detects all signals, the set can be expressed as:

S＝S₁∩S₂∩...∩S_M

the initial position estimation of the full-water-area target search mainly comprises the steps of selecting a main positioning array element, selecting a positioning auxiliary array element based on a template matching method and a least square method, selecting a deblurring auxiliary array element based on a minimum azimuth angle difference, and positioning TDOA time difference, and a flow chart is shown in fig. 8.

The specific contents are as follows:

(1) main array element selection

Selecting the geometric center (x) of each detection array element_c,y_c,z_c) The most recent array element is the main array element, and the algorithm formula is as follows:

(2) secondary array element selection based on template matching method and least square method

The selection steps of the auxiliary array elements are as follows:

1) calculating each detecting array element to positioning main array element (x)₀,y₀,z₀) A distance r of_i(i＝¹,2,...,Num-1)：

Selecting r_iThe detection array element point set with the length more than or equal to the required base line length is recorded as a set S (x)_i,y_i,z_i)，i∈[0,Num1](Num1 is less than or equal to the total number of the detection array elements).

2) Coordinate transformation

To locate the main array element x₀,y₀,z₀And taking the east direction as an X axis, the north direction as a Y axis and the Z axis vertical to the XY plane as a positive direction to establish a space rectangular coordinate system. Converting the set S into a space rectangular coordinate system, projecting the set S to an XY plane, and recording the XY plane as S_xy(x_i,y_i) And then S is_xy(x_i,y_i) Conversion to polar S_rθ(r_i,θ_i). As shown in fig. 9.

3) Positioning pair array element selection based on template matching method and least square method

In fig. 9, the azimuth angles of OA, OB, and OC are respectively 0 °,120 °, 240 °, and the OA, OB, and OC are used to form a Y-shaped array template.

Rotating the Y-shaped array by 120 degrees along the anticlockwise direction, stepping by 1 degree, and respectively calculating a set S of the Y-shaped array at different rotation angles_rθ(r_i,θ_i) The sum of the squares of the differences in azimuth angles with OA, OB, and OC, i.e.:

wherein j represents a rotation angle of the Y-shaped array, and θ_OA(j)、θ_OB(j)、θ_OC(j) The azimuth angles of OA, OB and OC at different rotation angles of the Y-shaped array are shown respectively.

Selecting min (. DELTA.)_azimuth(j) The corresponding 3 sub-array elements are positioning sub-array elements.

4) And selecting the deblurring auxiliary array elements based on the minimum azimuth angle difference.

Setting 3 positioning auxiliary array elements at A₁、B₁、C₁Dots, as shown in fig. 10. Respectively calculate the angle A₁OB₁、B₁OC₁、A₁OC₁Azimuth angle of the center line, respectivelyAnd

in the set S_rθ(r_i,θ_i) Deletion in A₁、B₁、C₁Point, is denoted as S_AM(r_i,θ_i) Separately computing the set S_AM(r_i,θ_i) And andthe square of the difference, i.e.:

i belongs to [1, total number of array elements-4 ]

Selecting min (. DELTA.)_θAB1(i),Δ_θBC1(i),Δ_θAC1(i) The corresponding array element is selected for the deblurring sub-array element.

5) TDOA positioning

Calculating TDOA between each secondary array element and the main positioning array element, and realizing preliminary position estimation (x) of full-water-area target search by applying TDOA positioning_Yi,y_Yi,z_Yi)。

S2: accurate position estimation of a target

The underwater target accurate position estimation is to utilize a Y-shaped positioning result, select a T-shaped positioning auxiliary array element in a self-adaptive manner and realize the high-precision positioning of the target by applying time difference positioning. The method mainly comprises the steps of selecting a positioning auxiliary array element based on a template matching method and the minimum azimuth angle difference, selecting a deblurring auxiliary array element based on the minimum azimuth angle difference, and positioning TDOA time difference, and is shown in figure 11.

The specific contents are as follows:

(1) secondary array element selection based on template matching method and minimum azimuth angle difference

1) Construction of standard T-shaped formation template

And projecting the target i to an XY plane, and calculating the azimuth angle of M by assuming the projection point to be M. Constructing a standard T-shaped array template A by taking a connecting line OM of main array elements O and M as a reference₁OB₁C₁As shown in fig. 12. Calculate OA separately₁、OB₁、OC₁Is measured.

2) Positioning pair array element selection based on minimum azimuth angle difference

Separately calculate the set S_rθ(r_i,θ_i) And OA₁、OB₁、OC₁And selecting 3 receiving array elements with the minimum azimuth difference as T-shaped positioning auxiliary array elements according to the square of the azimuth difference, namely:

3) deblurring auxiliary array element selection based on minimum azimuth angle difference

Azimuth angle theta of OM_MAs a basis, a set S is calculated_rθ(r_i,θ_i) And theta_MThe difference between:

and selecting the receiving array element with the minimum azimuth angle difference as a deblurring auxiliary array element.

4) TDOA positioning

Calculating TDOA between each secondary array element and the main positioning array element, and realizing accurate position of underwater target by using TDOA positioningEstimate (x)_Ti,y_Ti,z_Ti)

Preferably, the invention further comprises an autonomous formation planning underwater acoustic positioning system based on the cylindrical array, and the system executes any method step of the method.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.