Helicopter delivery of multi-cyclic sonar buoy

Abstract

The application discloses a method for a helicopter to drop multi-circle sonar buoys, which comprises the following steps: determining the position of a detection point, and then formulating a flight route of the helicopter; formulating a search scheme for deep water areas; a submarine attacks a platform K along a straight line direction from N to K, an enemy submarine is detected at the point N, the helicopter sets off from the point B to search and locks the position of the submarine at the point M, the arc length of an arc PKQ on which one buoy is approximately replaced by the diameter of the buoy, then the length of the arc PKQ is divided by the diameter of the buoy, and an integer after solving plus 1, so as to ensure full coverage of the boundary of a safe area C in the deep water area; the number of the first circle of buoys to be dropped and the position of the detection point in the outermost circle are determined; and a model for dropping buoys from the second layer to the last layer is established. The method fully utilizes existing resources, is suitable for a conventional search for any important platform as a determined point, has a regular distribution of detection points, and is easy to establish a model, and ensures the safety of the sea area around the platform.

Description

Technical Field

[0001] This invention belongs to the field of anti-submarine technology, and in particular relates to a method for deploying multi-circle sonar buoys by helicopter. Background Technology

[0002] As submarines continue to develop towards higher speeds, deeper depths, and lower noise levels, effective submarine search is the primary factor determining the success or failure of anti-submarine warfare. Therefore, in practice, it is necessary to consider factors such as the uncertainty of target location, the impact of the marine environment, the effectiveness of search equipment, and the uncertainty of external information. From the perspectives of maximizing search probability, minimizing search time, and minimizing resource consumption, and based on the battlefield situation, making full use of various means, scientifically designing flight routes and search methods is the key to solving this problem.

[0003] Aircraft-based anti-submarine warfare (ASW) search will be a crucial search method in future ASW operations. A vital facility, platform K, is located in the center of a nearshore area. An 80×80 nautical mile square area centered on platform K constitutes its safe zone. An ASW helicopter landing platform, equipped with two helicopters, is located at point B in shallow waters near the shore. To prevent platform K from being attacked and damaged by enemy submarines, regular patrols and searches of the safe zone surrounding the platform are necessary. Given the mission of protecting this important facility, an effective, reliable, and time-efficient conventional search plan for the entire protected area needs to be designed using helicopter ASW equipment. Summary of the Invention

[0004] To simplify the problem, this invention makes the following assumptions: A crucial facility platform K is established at the center of a nearshore sea area. An 80 × 80 nautical mile square area centered on platform K is designated as the platform's safe zone, where the gray area represents shallow water and the white area represents deep water. An anti-submarine helicopter landing platform is located at point B in the shallow water near the shore. To ensure the normal operation of platform K, frequent patrols and searches of the safe zone surrounding the platform are necessary to prevent damage and attacks from enemy submarines. Two anti-submarine helicopters are stationed at platform B.

[0005] This invention discloses a method for deploying multi-circle sonar buoys by helicopter, comprising the following steps:

[0006] Once the location of the detection point is determined, the flight route of the helicopter will be planned.

[0007] A deep-water search plan is formulated, with the radius of the safe zone C centered on platform K as R1. The passive sonar buoy signal deployed by the helicopter completely covers the boundary of platform K in the deep water area. The radius R1 includes the torpedo range L0 and the length S outside the torpedo range area.

[0008] The submarine attacks the platform K along the straight line from N to K, the enemy submarine is detected at N point, the helicopter starts searching from B point (x0, y0) and locks the submarine position at M (x M ,y M ) point after searching,

[0009] The time t and R1 used by the submarine from N to M point are calculated, and the safety area C is made with K as the center and R1 as the radius;

[0010] A plane rectangular coordinate system with K point as the coordinate origin and the same direction as the original coordinate system is established;

[0011] The intersection points P (x P , y P ) and Q (x P , -y P ) of the safety area C and the shallow water boundary are determined;

[0012] The number of detection points depends on the length of the arc PKQ in the safety area C, the diameter of the buoy is approximated to replace the arc length of a buoy on the arc PKQ, and then the length of the arc PKQ is divided by the diameter of a buoy, and the integer after solving is taken plus 1, which ensures full coverage of the boundary of the safety area C in deep water;

[0013] The number of the first circle of buoys is determined, and then the positions of the outermost circle of detection points are determined;

[0014] The model of the second layer to the last layer of the floating buoys is established.

[0015] Further, the time t used by the submarine from N to M point is calculated as follows:

[0016]

[0017] Calculate .

[0018] Further, the intersection points P (x P , y P ) and Q (x P , -y P ) of the safety area C and the shallow water boundary are determined by solving the equation set:

[0019]

[0020] .

[0021] Further, the number of the first circle of buoys is calculated as follows:

[0022] The number of the first layer of floating buoys is the number of the first circle of buoys, and D0 is the diameter of the floating buoys.​

[0023] The coordinates of the detection points are O ij (x ij ,y ij ), when i=1, the coordinates of the detection points on the first circle are obtained according to bisecting the central angle , from top to bottom, they are the first point, the second point, and so on:

[0024]

[0025]

[0026]

[0027] .

[0028] Further, the positions of the detection points on the outermost circle are determined, the outermost circle is close to the boundary to deploy the floaters, and the difference between the radius of the outer circle of the first circle of the deployed floaters and the radius of the inner circle of the last circle of the deployed floaters is calculated:

[0029] d= 40-(R1 + 4.3)-D0 = 27.1 –R1.

[0030] The number of the circles of the floaters that still need to be deployed is: , that is, the difference between the inner diameter of the circle ring is divided by the number n of the circles of the deployed floaters, m=d / n, which is the width of each circle of the floaters that still need to be deployed, D0 is the diameter of the deployed floaters, at this time, the floaters are selected to be deployed on the middle circle of the difference between the inner diameter of the circle ring.

[0031] Further, a model for deploying the floaters from the second layer to the last layer is established as follows:

[0032] Taking K as the polar coordinate point, the KT direction is the polar coordinate direction, and the center coordinates of the deployed sonar floaters are O ij (x ij ,y ij ), the central angle corresponding to the center in the polar coordinate is , i is the number of layers of the deployed sonar floaters, j is the number of the deployed sonar floaters on each circle of the sonar,

[0033] , , ,…

[0034] G represents the number of the first layer of the deployed sonar floaters, is;

[0035] Similarly, we have:

[0036] , , (1)

[0037] The relationship between the angles is as follows:

[0038] , , ,…

[0039] Adding both sides of the above equation, the following is obtained by simplifying:

[0040] The above equation is brought into equation (1) to obtain

[0041]

[0042] Because the center coordinates O ij (x ij ,y ij ) of the circle are R i , the following is derived:

[0043]

[0044]

[0045] Where R2=R1+D0 / 2+d / 4, R3=R1+ D0 / 2+3d / 4, R4=R1+ D0 / 2+5d / 4, …, R i =R1+ D0 / 2+(2i-3)d / 4.

[0046] The beneficial effects of the present application are as follows:

[0047] The present application makes full use of existing resources, is suitable for regular search of any important platform as a determination point, detects point distribution law, the model is easy to establish, and the safety of the platform and the surrounding sea area is ensured as much as possible. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 One of the sea area schematic diagrams of the present application;

[0049] Figure 2 The second sea area schematic diagram;

[0050] Figure 3 The angle relationship schematic diagram;

[0051] Figure 4 The first detection point distribution diagram;

[0052] Figure 5 The second detection point distribution diagram;

[0053] Figure 6 The first improved detection point distribution diagram;

[0054] Figure 7 Improved detection point distribution map with closed curves. Detailed Implementation

[0055] The present invention will be further described below with reference to the accompanying drawings, but this is not intended to limit the present invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0056] Table 1. Symbol Explanation

[0057]

[0058] Model building

[0059] In conventional searches, the helicopter's flight path needs to be determined based on the location of the buoy detection points. Therefore, this invention considers determining the location of the detection points first, and then formulating the helicopter's flight path. The core of the search area is the important facility platform K. The purpose of conducting conventional searches is to prevent the facility platform K from being attacked and damaged by enemy submarines. Therefore, considering its importance, the deep-water search plan must ensure the safety of K. Let the safe zone C be centered on K. Figure 1 The radius of the gray area is R1. Radar patrols and searches of the sea area can meet the requirements for short-term reconnaissance of the entire area. Within an 80×80 safe zone, the E-type submarine, carrying torpedoes, has a range of 10 nautical miles. Therefore, we define the danger zone as a circular area with a radius of 10 nautical miles centered on platform K (40, 40). To ensure the absolute safety of platform K, the anti-submarine aircraft radar detection area must constantly cover the entire danger zone. Therefore, the anti-submarine aircraft detection area constantly forms an inscribed circle with the danger zone, moving in a circular trajectory with a radius of 20 nautical miles around K.

[0060] The passive sonar buoy signal deployed by the helicopter must fully cover the boundary of platform K in the deep water area. R1 consists of two parts: one part is the torpedo range of 10 nautical miles, which avoids direct torpedo attack on platform K. However, 10 nautical miles is not enough to protect platform K. When our side detects the enemy submarine, the helicopter still needs a certain amount of flight and search time to reach the target point (since the speed difference between the helicopter and the enemy submarine is large, the search time is negligible). To ensure that the position of the enemy submarine when intercepted is also outside the 10 nautical mile area, let the length of the second part be S. The submarine attacks platform K along the straight line from N to K. The enemy submarine is detected at point N, and our side immediately dispatches a helicopter to search and then lock the position at point M (to determine the minimum safety radius, let point M be located at the boundary of the 10 nautical mile area). Let the time taken for the enemy submarine to travel from N to M be t, which is also the time taken for our side to travel from point B to point M. Assume that the data includes the coordinates of point B (30, 40), V 敌潜艇 V 直升机 Let the coordinates of point M be (xM ,y M ),

[0061]

[0062] To ensure adequate safety, the maximum value of t is taken, i.e. M point is located in the figure D point (D is the intersection of BM extension line and the boundary of the safety area),

[0063]

[0064] The distance of NM is

[0065] Further, the

[0066] When R1 is determined, a safety area C is made with K as the center and R1 as the radius. To facilitate the calculation of the coordinates of the detection points, a plane rectangular coordinate system is established with K point as the coordinate origin and in the same direction as the original coordinate system (for example Figure 2 ). Let the safety area C intersect the shallow water area boundary at P(x P , y P ) and Q(x P , -y P ). Through simultaneous solution of the equation group:

[0067]

[0068]

[0069] Since the number of detection points depends on the length of the arc PKQ of the diving boundary in the safety area C, to simplify the operation, the diameter of the buoy is approximately replaced by the arc length of one buoy on the arc PKQ, and then the length of the arc PKQ is divided by the diameter of one buoy. After solving, take the integer plus 1, which can ensure the full coverage of the safety area C boundary of the deep water area. The specific algorithm is as follows:

[0070] The number of the first layer of buoys (G is the number of the first circle of sonar buoys) , the first layer of buoy center coordinates are calculated as follows:

[0071] In triangle PKQ, the side |PK| = R1, |QK| = R1, |PQ| = 2, y p =

[0072] According to the cosine law of triangle, the angle , , then the arc length corresponding to the angle is (T coordinates (R1, 0)), divided by the diameter of the buoy 8.6, and the result after taking the integer plus 1 is: ​The number of the first circle of the buoy.

[0073] The coordinates of the detection point is O ij (x ij ,y ij ) When i = 1, according to the bisector of the central angle , the coordinates of the first circle of the detection point (from top to bottom, the first point, the second point...) can be obtained (as shown in Figure 3 ):

[0074]

[0075]

[0076]

[0077]

[0078] After the first circle is determined, the position of the outermost circle of the detection point is determined. Since the 11th sea area has the highest probability of searching for a submarine, the outermost circle should be close to the boundary to launch the buoy. The difference between the outer circle radius of the first circle of the buoy and the inner circle radius of the last circle (as shown in Figure 4 ) of the buoy is

[0079] d = 40 - (R1 + 4.3) - 8.6 = 27.1 - R1.

[0080] The number of circles that still need to launch the buoy: (rounding the value of , 8.6 is the diameter of the buoy), that is, the difference between the inner diameter of the circle ring divided by the number of circles n, m = d / n, which is the width of each circle (m in Figure 2 ) that still needs to launch the buoy. At this time, the buoy is selected to be launched on the middle circle of the difference between the inner diameter of the circle ring.

[0081] Considering that the enemy submarine travels in a straight line, the second circle of the buoy should be launched in the gap between the first layer of two buoys. To simplify the calculation of the coordinates of the center, the center of the second layer is determined by half of the angle between the two centers of the first layer. From the second layer of the buoy to the last layer of the buoy, the following model is established:

[0082] Taking K as the polar coordinate point, KT direction as the polar coordinate direction, and the center coordinates of the launched sonar buoy as O ij (x ij ,y ij ), the corresponding center angle of the center in polar coordinates is , i is the number of layers of the launched sonar buoy, and j is the number of the launched sonar buoy on each layer of the launched sonar buoy.

[0083] , , ,…

[0084] Similarly, we can get:

[0085] , , (1)

[0086] From Figure 5 we can more clearly show the relationship between angles:

[0087] Induction:

[0088] , , ,…

[0089] Add the two sides of the above equation, and get:

[0090] Bring the above formula into (1), we get

[0091]

[0092] Because the center of the circle O ij (x ij ,y ij ) is the radius of R i , we derive:

[0093]

[0094]

[0095] Where R2=R1+4.3+d / 4, R3=R1+4.3+3d / 4, R4=R1+4.3+5d / 4, …, R i =R1+4.3+(2i-3)d / 4, when i=n+2, R n+2 =40-4.3=35.7.

[0096] Conclusion: With the help of MATLAB, we can calculate the coordinates of the sonar buoy point, and we know that the first circle needs to be launched 6 buoys, and the outer circle is one more than the inner circle, a total of 4 circles 30 sonar buoys, and the detection point distribution is drawn as Figure 4 and Figure 5:

[0097] Through the buoy distribution map, we can see that the detection points on the edge of the third and fourth circles are distributed in shallow water, so we determine that when the horizontal coordinate of the detection point is less than the horizontal coordinate of the intersection point of the detection point circle and the shallow water boundary, no more buoys will be launched, and the improved buoy distribution is as follows Figure 6 .

[0098] According to the distribution map of the detection points, the number of the floating markers is 26, three helicopters are needed, one helicopter carries 9 floating markers, two helicopters simultaneously drop the floating markers, and the whole detection can be completed in two times. In order to ensure the least time, 26 detection points are divided into three layers according to the size of the longitudinal coordinate, and the three layers are connected into three single closed curves, each single closed curve connects 9, 8 and 9 detection points, wherein route 1 and 2 are the simultaneous search routes of two helicopters, and route 3 is the second search route of one helicopter from B point, the final result is calculated by Matlab, the time of route 1 and 2 is 1.032 hours, the time of route 3 is 1.0868 hours, and the total search time is 2.1188 hours without considering the preparation time between two searches. Figure 7

[0099] The beneficial effects of the present application are as follows:

[0100] The present application makes full use of the existing resources, is suitable for the conventional search of any important platform as a determined point, the detection point distribution law is easy to establish, and the safety of the platform and the surrounding sea area is ensured as much as possible.

[0101] The word "preferred" is used herein as a term of art to denote features that can be used in the examples, embodiments, or examples. Any aspect or design described herein as "preferred" is not necessarily to be construed as more advantageous than other aspects or designs. Rather, the use of the word "preferred" is intended to present a concept in a specific way. The term "or" as used in this application is intended to mean inclusive "or" rather than exclusive "or". That is, unless otherwise specified or clear from context, "X uses A or B" means that any one of the arrangements is naturally included. That is, if X uses A; X uses B; or X uses both A and B, "X uses A or B" is satisfied in any of the foregoing examples.

[0102] ​Moreover, although the present disclosure has been illustrated and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based on the foregoing description and accompanying drawings. The present disclosure includes all such modifications and alterations and is limited only by the scope of the following claims. In particular regard to the various functions performed by the above described components (e.g., elements, engines, modules, etc.), the terms used to describe such components are intended to correspond, where appropriate, to any component which performs the specified function (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the present disclosure. In addition, while a particular feature of the disclosure can have been disclosed with respect to only one of several implementations, such feature can be combined with one or other features of the other implementations as can be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms "including", "includes", "having", "has", "contain", "contains", or variants thereof to be afforded similar meanings in the context of describing common ownership in the background portion of the detailed description are used, such terms are intended to be inclusive in a manner similar to the term "comprising" as comparable terms under the doctrine of equivalents in the field of patent law.

[0103] The various functional units in the embodiments of the present application can be integrated in one processing module, or each unit can exist physically, or a plurality of or more units can be integrated in one module. The integrated module can be realized in the form of hardware, or in the form of a software functional module. When the integrated module is realized in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer readable storage medium. The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc. The above-mentioned devices or systems can execute the storage method in the corresponding method embodiments.

[0104] In summary, the above embodiments are one embodiment of the present application, but the embodiments of the present application are not limited by the above embodiments, and any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principle of the present application are equivalent replacement methods and are included in the protection scope of the present application.

Claims

1. A method of helicopter delivery of a multi-cyclic sonar buoy, characterized in that, The method comprises the following steps: Determine the position of the detection points, and then make the flight route of the helicopter; Make a search scheme for the deep water area, wherein the radius of the safety area C with the platform K as the center is R1, the passive sonar buoy signal dropped by the helicopter completely covers the boundary of the platform K in the deep water area, and the radius R1 includes the torpedo range L0 and the length S outside the torpedo range area; The submarine attacks the platform K along the straight line direction from N to K, the enemy submarine is detected at N point, the helicopter locks the submarine position at M (x M ,y M ) point after searching from B point (x0, y0), Calculate the time t used by the submarine from the point N to the point M and R1, and make the safety area C with K as the center and R1 as the radius; K platform coordinates are , establish a plane rectangular coordinate system with K point as the coordinate origin and the same direction as the original coordinate system; determining intersection points P(x P , y P ) and Q(x P ,-y P ) of the safety zone C and the shallow water area boundary line; The number of the detection points depends on the length of the arc PKQ of the shallow water boundary in the safety area C, the arc length of one buoy on the arc PKQ is approximately replaced by the diameter of the buoy, and then the length of the arc PKQ is divided by the diameter of the buoy to obtain an integer plus 1, so as to ensure the full coverage of the boundary of the safety area C in the deep water area; Determine the number of the first circle of buoys, and then determine the position of the outermost circle of detection points; Establish the buoy dropping model of the second layer to the last layer; The specific algorithm of the number of the first circle of buoys is as follows: The number of the first layer of the floating objects The number of the first circle of the floating objects, D0 is the diameter of the floating objects The coordinates of the detection points are O ij (x ij ,y ij ), when i=1, the coordinates of the detection points on the first circle are obtained according to bisecting the central angle , from top to bottom, they are the first point, the second point, and so on. ； Determine the position of the outermost circle of detection points, drop the buoys close to the boundary in the outermost circle, and calculate the difference between the radius of the outer circle of the first circle of dropped buoys and the radius of the inner circle of the last circle of dropped buoys: d = 40-(R1 + D0 / 2)-D0 = 27.1-R1 The number of circles of the buoy to be put in is: The difference between the inner diameter of the circle ring divided by the number of circles of the buoy to be put in, m=d / n, is the width of each circle of the buoy to be put in, D0 is the diameter of the buoy to be put in, the diameter of the buoy is 8.6, and at this time, the buoy is selected to be put in on the middle circle of the difference between the inner diameter of the circle ring. The buoy dropping model of the second layer to the last layer is established as follows: K is the polar coordinate point, KT direction is the polar coordinate direction, and the center coordinate of the sonar buoy is O ij (x ij ,y ij ), the center angle corresponding to the center of the circle under the polar coordinate is i is the number of layers of the sonar buoy, and j is the number of sonar buoys on each layer of the sonar deployment circle ， ， ，... G represents the number of sonobuoy first layer deployment, is 2 - the result; Similarly, the following is obtained: ， ， （1） The relationship between the angles is as follows: ， ， ，..., Adding the above equations, we get: The above formula is brought into formula (1) to obtain Because the center of the circle O ij (x ij ,y ij ) is the radius of the circle R i , it is derived that: where R2 = R1 + Do / 2 + d / 4, R3 = R1 + Do / 2 + 3d / 4, R4 = R1 + Do / 2 + 5d / 4,..., R i = R1 + Do / 2 + (2i - 3)d / 4.

2. A method of helicopter delivery of a multi-cyclic sonobuoy according to claim 1, wherein, The time t used by the submarine from the point N to the point M is calculated as follows: Computing .

3. A method of helicopter delivery of a multi-turn sonobuoy according to claim 1 wherein, Determine the intersection points P(x P , y P ) and Q(x P , -y P ) of the safety zone C and the shallow water area boundary, by solving the system of equations: get .

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