RU2608583C1 - Method of determining position and motion parameters of object as per measurements of angular coordinates - Google Patents

Abstract

FIELD: acoustics.

SUBSTANCE: invention relates to hydroacoustics and can be used for determining position coordinates and motion parameters of an object according to data of passive hydroacoustic means using both one and several receiving antennae. Core of the method is, that bearings

at a noisy object moving with heading K_true and speed V_true obtained from each k of the hydroacoustic antennae are displayed in the form of a single matrix

of distributing the object position onto a plane, then the obtained matrices are shifted in the directions of the object possible movement while it keeps the heading K₁, K₂, …, K_m, … K_p and the speed, V₁, V₂, …,V_n, … V_r, they are brought to a single moment of time and subsequently summed up element by element, herewith it is considered that shift parameters (K_m, V_n) of summed up matrix M_mn containing an element with the maximum value mostly correspond to the object movement true parameters (K_true, V_true), and location of that element in matrix M_mn indicates the object true location on the plane.

EFFECT: technical result is the increase of accuracy and unification of methods of determining position coordinates and motion parameters of an object without maneuvering by the detection means carrier.

1 cl, 17 dwg

Description

The invention relates to hydroacoustics and can be used to determine the coordinates and motion parameters of the object according to passive surveillance tools.

Known methods for determining the location and motion parameters of an object by measuring the angular coordinates, when only the direction (bearing) is measured at the object (target), as is the case in sonar direction finding stations (hereinafter - GAS).

The determination of the coordinates and parameters of the target’s movement (KPDC) without performing special maneuvering by the GAS carrier (observer) is carried out in several ways - energy, dynamic, triangulation, horizontal differential-rangefinder and others [1]. These methods suggest the presence of at least two to three antennas spaced in the HAS. The application of these methods is complicated by the large dependence of the accuracy of determining the KPDTs on the distance between the GAS antennas and, as a consequence, the need for a large diversity of antennas within the same carrier, which is not always feasible.

Known methods for determining the efficiency of data from only one antenna GAS. The “n - bearings” method [2] provides the determination of KPDTs by sequentially taking samples of bearings in a straight and uniform section of the observer's movement and performing the subsequent maneuver, which allows one to determine KPTTs at the time of taking the last sample. The disadvantage of this method is unacceptably long (sometimes up to several tens of minutes) the time to solve the problem and the need for the observer to perform special maneuvering.

The methods “proofreading”, “selection”, “filtering” [3], the algorithm proposed in [4], as well as the method for determining the parameters of the movement of a maneuvering object [5] allow determining the KPDT without the observer performing special maneuvering using the data of one GAS antenna. The disadvantages of these methods are highly dependent on the availability and accuracy of the entered a priori information about the target; a high degree of operator load in the decision process, especially with a large number of goals; a significant dependence of the accuracy of determining KPDTs on the experience and qualifications of the operator.

Note. The term “operator” hereinafter denotes the operator of the combat information management system (CIMS), the integrated combat management system (ISBU) or other device by which the KPDK is determined on a specific GAS carrier.

The above methods for determining the KPDC are solved by various mathematical methods (least squares - “n-bearings”, “proofreading”; successive approximations - “selection”; Kalman filtering - “filtering” [3]) using significantly different algorithms and have a significantly different procedure solutions.

The closest in the amount of features analogue of the invention is the method of "n-bearings" [2, 3]. The prototype method includes determining the bearing and smoothing errors, detecting a signal from a maneuvering object, taking it for automatic tracking and classification. Measured at equal intervals of time t ₁ bearing on the target are used to build the trajectory of the target. The advantage of this method is that it does not require active intervention of the operator in the process of determining KPTDs, its disadvantages, in addition to the unacceptably long time to solve the problem and the need for special maneuvering, include the inability to use a priori information about the target, as well as the inability to determine KPDTs according to data from spaced antennas GAS.

These shortcomings limit the observer in the full implementation of the capabilities of the CEO, and as a result, in the implementation of the capabilities embodied in the carrier of the CEO as a whole.

The objective of the invention is to expand the functionality of carriers GAS (including differing in the composition and number of receiving antennas) to determine the location and motion parameters of the objects of observation.

The technical result from the use of the invention is to unify the task of determining KPTD according to the GAS, to minimize operator participation in the decision process, as well as to increase accuracy and reduce the time it is solved.

The problem is solved by determining a point on the plane, the probability density of finding the target in which with the available amount of input information is maximum.

A new significant feature of the invention is that the proposed method is universal: it can be used to determine the KPTD according to the GAS data, having both one and several receiving antennas, both mobile and stationary (including positional and stationary) GAS, both using a priori information about the target and the nature of its maneuvering, and without it.

Another significant feature of the invention is that the operator does not receive the unit values of the quantities that make up the KPDC (i.e., the course of the target, speed of the target and distance to it), but their probability distributions, which allows a more complete judgment about the location of the target and its nature movement.

Due to this, the load on the operator is reduced, especially with a large number of goals, the accuracy and quality of the solution to the problem of determining KPTDs are increased, and the time for its solution also decreases.

The invention is illustrated in FIG. 1-17.

In FIG. 1 shows the area of the possible position of the target in the presence (a) and absence (b) of information about the distance to the target.

- матрицы пеленгов, поступающие в моменты времени t₀-t₅.In FIG. 2 reflects the process of direction finding of the target, where

- bearing matrices arriving at time instants t ₀ -t ₅ .

In FIG. Figure 3 shows a fragment of a bearing matrix on a target (matrix size 300 by 300 elements) in the “initial” bearing segment.

In FIG. 4 shows a fragment of a bearing matrix on a target (matrix size 300 by 300 elements) in the “final” section of the bearing.

In FIG. 5 shows the geometric meaning of the method for determining the location and parameters of an object’s motion from measurements of angular coordinates in a situation where the calculated parameters of the target’s motion correspond to true ones.

In FIG. 6 shows the geometric meaning of the method for determining the location and parameters of the object’s motion from measurements of angular coordinates in a situation where the calculated parameters of the target’s motion do not correspond to the true ones.

In FIG. 7 shows the use of the method for determining the location and motion parameters of an object from the data of the main and towed HAS antennas.

In FIG. Figure 8 shows a fragment of the bearing matrix on the target when determining the location and parameters of the object’s movement according to the data of the main and towed HAS antennas (more precisely, two bearings, since the bearing from each HAS antenna have different values of both the bearing value and the standard error (RMS) direction finding).

In FIG. Figure 9 shows the use of the method for determining the location and motion parameters of an object according to the data of three onboard conformal GAS antennas.

In FIG. 10 shows a fragment of the bearing matrix on the target when determining the location and parameters of the object’s movement according to the data of three onboard conformal GAS antennas (more precisely, three bearings from each of the antennas, the application of which on top of each other taking into account the RMS of direction finding gives the indicated matrix).

In FIG. 11 shows the geometric meaning of the method of determining the location and parameters of the object’s motion according to the main GAS antenna, without maneuvering by the GAS carrier, with the introduction of a priori information about the sector of the possible target courses (and (or) the range of its speed, the range of possible distances to it).

In FIG. Figure 12 shows an example of the distribution of target motion parameters (a), target location (coordinates) (b), heading distribution (c) and target speed (d) 3 minutes after the start of solving the problem of determining the location and target motion parameters. FIG. 12c) and 12d) are two-dimensional projections of FIG. 12a), respectively, for the course (Fig. 12c)) and speed (Fig. 12d)) of the target.

In FIG. 13 shows an example of the distribution of the parameters of the target’s movement (a), the distribution of the location (coordinates) of the target (b), the course distribution (c) and the target’s speed (d) 6 minutes after the start of solving the problem.

In FIG. Figure 14 shows an example of the distribution of the parameters of the movement of the target (a), the distribution of the location (coordinates) of the target (b), the distribution of the course (c) and the speed of the target (d) 9 minutes after the start of solving the problem.

In FIG. 15 shows a table for assessing the accuracy of determining the location and motion parameters of the target according to the data of the main and towed HAS antennas.

In FIG. 16 shows a table for assessing the accuracy of determining the location and motion parameters of the target according to the data of three onboard conformal antennas of the HAS.

In FIG. 17 shows a table for assessing the accuracy of determining the location and motion parameters of the target according to the main GAS antenna, without maneuvering by the GAS carrier, with the introduction of a priori information about the sector of possible target courses, the range of its speed and the range of possible distances to it.

The method is as follows. The area of the possible position of the target on the plane (HVAC) at any time is a figure or region, which, as a first approximation, in the presence of information about the distance to the target can be depicted as an ellipse (Fig. 1a), and in its absence - in the form of a sector (Fig. 1b). The dimensions of these figures are determined by the errors in the knowledge of the target location - in this case, the standard deviation of direction finding σP and the standard deviation of the distance to the target σD.

When solving the problem by the method of determining the location and parameters of the object’s motion by measuring the angular coordinates (hereinafter referred to as the “method”), the distribution of the target is assumed to be uniform along the axis parallel to the bearing to the target, and normal - along the axis perpendicular to the bearing, the density of the distribution of the target’s location can be represented by the expression

where x, y are the coordinates of the target;

β is the angle of inclination of the scattering sector to the ordinate axis, in this case, the bearing to the target (in Fig. 1b) - P ₀ );

σβ - standard deviation of direction finding (in Fig. 1b) - σP);

σx (x, y) - standard deviation of the coordinates of the target along the minor axis of the scattering sector, determined, in turn, by the expression

Note. As follows from expression (1), the coordinate system is rotated through an angle β, therefore σx (x, y) is the standard deviation of the target’s coordinates along the axis perpendicular to the bearing on the target, and not its projection onto the abscissa axis in the original coordinate system.

Further, the obtained probability distribution must be reduced to the matrix form, which is performed as follows. The computational domain X is divided into n ² cells if it is necessary that the matrix is square, or n _x × n _y cells if the matrix should be rectangular. The discretization step along the Δx and Δy axes is also specified. Then the distribution of the target defined by the expression (1) can be represented in the form of a matrix p = (p _{i, j} ), where

x ₀ , y ₀ - coordinates of the observer (in Fig. 1b) - point L ₀ ).

Thus obtained matrix of the initial target distribution (hereinafter referred to as the bearing matrix) is normalized using the expression

- максимальное значение в матрице по столбцу с j-м номером.Where

is the maximum value in the matrix by the column with the jth number.

Note. Expression (4) is valid when the central axis of the scattering sector (hereinafter, the bearing axis) is located along the abscissa. As the axis of the bearing approaches the axis of the quadrant of the coordinate system, expression (4) must be converted to

- максимальное значение в матрице по строке с i-м номером.Where

- the maximum value in the matrix on the line with the i-th number.

Thus, such a distribution is obtained when on the bearing axis all elements of the matrix are equal to 1, and normal to the axis perpendicular to the axis with the value σx defined by expression (2). The matrices of other bearings coming from the HAC during the determination of the efficiency factor are determined similarly (Fig. 2), fragments of these matrices are shown in Figs. 3-4.

The geometric meaning of the method is shown in FIG. 5. The matrices of all bearings are reduced to one point in time (more conveniently, to the time of the last bearing), after which they are summed for each k-th combination “target course - target speed” using the expression

where F _k is the total matrix of the kth combination "target course - target speed";

N is the number of summed bearings (matrices);

ƒk _n is the matrix of the nth bearing in the kth combination “target course - target speed”, where n = 1 ... N;

r is a constant designed to more clearly isolate the maximum.

Then, in each matrix F _k , a maximum search is performed for max (F _k ). The found maxima are normalized and compared with each other, and the matrix F _k that contains the cell max (F _k ), whose value is 1, is considered to be most relevant to the real parameters of the target’s movement (in Fig. 5, this cell corresponds to the intersection point of all “displaced »Bearings with bearing P ₅ ). Accordingly, the placement of this cell in the indicated matrix corresponds to a point on the plane where the distribution density of the target is maximum, i.e. target location.

If the combination “target course - target speed” does not correspond to reality, then a pronounced intersection of the moved bearings at one point does not work (Fig. 6) and, accordingly, the maximum value max (F _k ) for such a total matrix will be less than that of the matrix corresponding to the true (or close to those) parameters of the target’s movement.

The reduction of bearing matrices to one point in time is carried out using the expression

where ƒ ₀ is the matrix of a certain bearing obtained using expression (4) or (5);

в направлении

(k - номер комбинации «курс цели - скорость цели»;ƒ _k is the matrix of a bearing displaced parallel to itself by a distance

in the direction

(k is the number of the combination “target course - target speed”;

,

, t_k - соответственно, курс, скорость и время прямолинейного движения цели при k-й комбинации «курс цели - скорость цели»;

,

, t _k - respectively, the course, speed and time of the rectilinear movement of the target with the k-th combination "target course - target speed";

round (x) is an operator showing the integer closest to x;

Δx and Δy are the discretization steps along the x and y axes, otherwise, the size of the elements of the bearing matrices.

When determining the KPDK according to the data of two (main and towed) HAS antennas, the method does not undergo practically any changes, the only difference is some complication of calculation of bearing matrices. Suppose a HAS carrier receives target information using, in this case, two antennas, each of which has its own direction finding accuracy (Fig. 7). Let ƒ _n1 be the matrix of the nth bearing received from the first antenna (main HAS antenna), as described above, ƒ _n2 be the matrix of the nth bearing received from the second antenna (a towed antenna that has less direction finding accuracy than main antenna). Then the matrix of the nth bearing (and, in fact, two bearings, since the bearing on the target from each of the antennas will be different) can be obtained using the following expression

A fragment of such a matrix is shown in FIG. 8.

Accordingly, when determining the KPDK according to the data of three onboard conformal HAS antennas (Fig. 9), the matrix of the nth bearing (and, in fact, three bearings) can be obtained using the expression

A fragment of this matrix is shown in FIG. 10.

In FIG. 11 shows the geometric meaning of the method for determining the location and motion parameters of an object from the data of the main GAS antenna, without maneuvering by the GAS carrier, with the introduction of a priori information about the sector of the possible courses of the target (and (or) the range of its speed, the range of possible distances to it). These restrictions are introduced by limiting the size of the matrices by the distance to the target, as well as by setting the number of combinations “target course - target speed”.

Being plotted (Fig. 12), the above maxima max (F _k ) give an idea of the nature of the distribution of the parameters of the target’s movement, as well as the extent to which this or that combination “target course - target speed” prevails over the others. As the observation time and, accordingly, the time of solving the problem increase, the nature of the distribution of the target’s motion parameters changes (Fig. 13 - Fig. 14), which allows more accurate identification of the true values of the KPTD or, conversely, the conclusion about the need to make a maneuver, continue observation current course etc.

The task of assessing the effectiveness of a particular method for determining KPDTs is not in itself trivial. For example, in [6], a methodological apparatus was proposed for substantiating the requirements for the accuracy of determining KPDT according to the GAS data. As a rule, the key quantities in relation to which the effectiveness of one or another algorithm for determining KPTD is determined are the time to solve the problem at a given distance to the target. However, it is known [2, 3] that the errors in determining the KPDK for different values of the target angle of the target manifest themselves in different ways, for example, sharp heading angles show a greater error in the heading, at heading angles close to straight - in the distance, etc. . Thus, the “behavior” of the errors in determining the KAPC must be investigated not only depending on the time of determining the KPDC, but also on the situation of changing the relative position of the carrier of the CEO and the target.

, в свою очередь, также изменяется от 10° до 90°.Based on the foregoing, the effectiveness of the method was assessed for the following conditions of convergence of the observer and the target: observer course - Kl = 0 °, observer speed Vl = 6 knots, target course Kts = 180 °, target speed Vts = 12 knots, initial distance to goals - 100 cab. The time for solving the problem is 3, 6, 9 and 12 minutes from the moment of detection of the target. The target detection bearing varies from 10 ° to 90 °, i.e. starting heading angle

in turn also varies from 10 ° to 90 °.

, град.), СКО скорости цели (

, в процентах от истинной скорости цели) и СКО дистанции до цели (σD в процентах от текущей дистанции) приведены на фиг. 15-17.Evaluation of the accuracy of the solution of the problem of determining the location and parameters of the object’s movement in the proposed way - the standard deviation of the target (

, deg.), standard deviation of target speed (

, as a percentage of the true target speed) and the standard deviation of the distance to the target (σD as a percentage of the current distance) are shown in FIG. 15-17.

In FIG. 15 shows the results of evaluating the accuracy of determining the location and motion parameters of an object using a towed HAS antenna (Fig. 7). The standard deviation of the direction finding of the main HAS antenna is assumed to be 0.15 °, the standard deviation of the direction finding of the towed HAS antenna is 0.3 °, the distance between the acoustic centers of the antennas is 1000 meters.

In FIG. 16 shows the results of evaluating the accuracy of determining the location and parameters of the object’s movement according to the data of three onboard conformal GAS antennas (Fig. 9), the standard deviation of direction finding of all antennas is taken to be 0.15 °, the distance between the antennas is 40 meters.

In FIG. 17 shows the results of evaluating the accuracy of determining the location and motion parameters of the target according to the main GAS antenna, without maneuvering by the GAS carrier, with a priori information about the sector of possible target courses, the range of its speed and the range of possible distances to it. The standard deviation of direction finding is taken equal to 0.3 °. Introduced restrictions: sector of the target courses ± 30 ° (i.e., Kc min = 150 °, Kc max = 210 °), speed range ± 25% (i.e., Uc min = 9 knots, Uc max = 15 knots ), the range of distances is ± 30% (i.e., D min = 70 cab., D max = 130 cab.).

Comparison of the presented results with the results obtained by other methods for determining KPDC [1, 3, 4] shows that the proposed method has greater accuracy at an equal time to determine KPDC, and also has the universality property both with respect to the composition of the GAS and to the composition of a priori information about the goal.

The proposed new method for determining the location and parameters of the object’s motion by measuring the angular coordinates can be implemented in the BIUS (ISBU) of modern and promising GAS carriers. The method can replace all currently existing methods for determining KPDTs - "n - bearings", "proofreading", "selection", "filtering". The implementation of the method does not require special professional skills from the operator, while the effectiveness of these “traditional” methods is largely determined by the experience and qualifications of the operator.

Information sources

1. Mashoshin A.I. Synthesis of an optimal algorithm for passively determining the distance to a target. // Marine Radio Electronics, Vol. 2 (40), 2012 .-- S. 30-34.

2. Skvortsov M.I. Basics of maneuvering ships [Text] / M.I. Skvortsov, I.V. Yuhov, B.I. Zemlyanov et al. - M .: Military Publishing House, 1966 .-- 270 p.

3. Polenin V.I. Methods and tasks of determining the coordinates and parameters of target movement according to the SAC of submarines [Text]: monograph / V.I. Polenin. - SPb .: VMA them. N.G. Kuznetsova, 2003 .-- 103 p.

4. Grinenkov A.V., Mashoshin A.I., Savvateev K.F. An algorithm for automatically determining the coordinates and parameters of target movement without special maneuvering of the observer. // Marine Radio Electronics, Vol. 4 (50), 2014 .-- S. 50-57.

5. RF patent, No. 2196341 IPC G01S 3/80, 11/01/2001 - A method for determining the motion parameters of a maneuvering object.

6. Zakharov V.L., Mashoshin A.I. The methodological apparatus for substantiating the requirements for the accuracy of determining the coordinates and parameters of the movement of targets according to the information of the sonar complex of the submarine. // Marine Radio Electronics, Vol. 4 (38), 2011 .-- S. 36-39.

Claims (2)

A method for determining the location and motion parameters of an object from measurements of angular coordinates, including receiving an acoustic noise signal from a maneuvering object by antenna A or antennas A1, A2 ... Ak of the sonar acoustic complex, where k is the number of antennas, converting the acoustic noise signal into electrical, preliminary amplification and primary processing received signal, automatic tracking of the object by angle, its classification and sequential measurement of bearings

or sets of bearings

;

;

at time t ₁ , t ₂ , ... T on the object maneuvering the course K _East and speed V _East , characterized in that the received bearing or a set of bearings are displayed in the form of matrices P ₁ , P ₂ , ... P _{m the} distribution of the position of the object on the plane, after which the indicated matrices are shifted in the directions of possible movement of the object when it moves with the course of K ₁ , K ₂ , ... To _p , where p is the number of values of the object’s course, the distance traveled by it with speed V ₁ , V ₂ , ... V _r , where r is the number of values of the object’s speed, during t ₁ , t ₂ , ... T, and the subsequent element-wise summation matrices obtained, it is considered that the shift parameters ha of the resulting total matrix, which contains the element with the maximum value, to the greatest extent correspond to the true parameters of the movement of the object maneuvering the course K _East and speed V _East , and the location of this element in this matrix indicates the true location of the object on the plane.

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