Object putting method based on position relation between aircraft and underwater object

Abstract

The invention discloses an object throwing method based on the position relation between an aircraft and a submarine, and the method comprises the steps: calculating the flight time of a bomb hitting the center of a submarine when the depth of the submarine is h, calculating the flight time of the bomb when the depth of the submarine has an error, calculating the curve equation of the flight of the bomb, and calculating the position coordinates of the bomb hitting the submarine. Calculating an initial coordinate and a departure center position of the position at the moment that the aircraft launches a bomb; when the change quantity (delta x, delta y) exists in the xoy plane coordinate system, the coordinate of the point in x'oy 'is calculated; the optimal bomb dropping opportunity can be accurately obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation anti-submarine, and in particular relates to an object dropping method based on the positional relationship between an aircraft and a submerged object. Background Art

[0002] In the joint sea and air operations under information conditions, bombers need to attack targets on the sea surface and underwater. In order to effectively strike the targets, analyzing and discussing the best time to drop bombs in the air is the most critical issue.

[0003] Generally speaking, the accuracy of bombing by an aircraft is related to factors such as the speed, altitude, and direction of the flight, the location, size, speed, and direction of the target, the size and weight of the bomb, the wind speed and direction at sea, and the density and depth of the seawater. If the bomb is approximately spherical, it has no power itself and will explode as soon as it touches the target. The closer the impact point is to the center of the target, the greater the damage to the target. In actual situations, the depth of the target underwater is often not fixed. Within a certain range, the best time to drop the bomb needs to be determined based on the target's diving depth range. Summary of the invention

[0004] The present invention proposes an object dropping method based on the positional relationship between an airplane and a submerged object. By analyzing the trajectory equations of a bomb and a submarine, the relationship between the bomb's impact point deviation and the submarine's diving depth error is found, and the conclusion is that the smaller the submarine's depth h is, the smaller the impact point deviation is. Secondly, considering the length and width of the submarine, in order to hit the submarine as much as possible without hitting the center of the submarine, the present invention provides the necessary and sufficient conditions for the submarine to be hit, thereby establishing a model for the best time to drop the bomb.

[0005] The object delivery method based on the positional relationship between an aircraft and a submerged object disclosed in the present invention comprises the following steps:

[0006] List the velocity component equations for the bomb:

[0007]

[0008] The curve equation of the bomb's motion is:

[0009]

[0010] Ship speed equation:

[0011]

[0012] The curve equation of the ship:

[0013]

[0014] From (2) and (4), we can get:

[0015]

[0016] In (2), z = 0, which gives the time the bomb is in the air.

[0017]

[0018] Obviously, the bomb can hit the ship when the x and y coordinates of the bomb and the ship are equal.

[0019] The present invention has the following beneficial effects:

[0020] The modeling idea of ​​the present invention is clear, the method of establishing the model is relatively simple and easy to understand; the established models are all given in mathematical formulas and are easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the bomb of the present invention in the air and in the water;

[0022] Figure 2 Rotation diagram of plane coordinate system. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the accompanying drawings, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0024] The present invention does not determine the specific diving depth of the submarine, but only gives a rough range. In order to solve this problem, the present invention first considers that when the submarine's diving depth has a certain error, the bomb's impact point will deviate, and the degree of deviation is related to the submarine's depth; for this reason, by analyzing the trajectory equation of the bomb and the submarine, the relationship between the bomb's impact point deviation and the submarine's diving depth error is found, and the conclusion is that the smaller the submarine depth h, the smaller the impact point deviation; secondly, considering the length and width of the submarine, in order to hit the submarine as much as possible without hitting the center of the submarine, the necessary and sufficient conditions for the submarine to be hit are given, so as to establish a model for the best time to drop the bomb; and using this model, it is concluded that when the wind direction is consistent with the flight direction of the aircraft and the direction of the submarine is opposite to it, the best time to drop the bomb is when the horizontal distance between the aircraft and the submarine is 3448 meters.

[0025] For the convenience of analysis, the present invention defines the problem as follows: there is a bomber with a flight speed of 200 meters per second and a flight altitude of 1000 meters; the radius of the bomb is 0.25 meters, and the density is 0.8×103 kg / m3; the wind speed at sea is 10 meters per second. The target is a nearly cylindrical submarine with a length of 100 meters and a maximum width of 9 meters. The target submarine may dive to a depth of 20-60 meters and travel at a speed of 15 knots. The relationship between the accuracy of the aircraft bombing and related factors is analyzed. For the target to be attacked, the best time for the aircraft to drop the bomb is determined according to the angle direction between the aircraft and the target movement, and the results of the model are simulated and tested.

[0026] 3. Problem Assumptions

[0027] Assumption 1: The aircraft's altitude remains constant while launching the bomb.

[0028] Assumption 2: The submarine's diving depth in the water remains unchanged.

[0029] Assumption 3: The angle at which the aircraft launches bombs can be adjusted freely.

[0030] Assumption 4: The bomb in the air is only affected by wind speed and its direction, without considering air resistance.

[0031] Assumption 5: When the bomb is running in seawater, the friction generated by the seawater is not considered.

[0032] The meanings of the symbols in the present invention are as follows:

[0033] α Angle between wind and x-axis β The angle between the bomb launch direction and the x-axis γ Angle between the ship and submarine's travel direction and the y-axis <![CDATA[v1]]> The initial velocity of the bomb <![CDATA[v2]]> Wind speed <![CDATA[v3]]> Speed ​​of ships and submarines <![CDATA[T1]]> The time the bomb falls in the air <![CDATA[T2]]> The total time the bomb was in the air and in the water g Gravitational acceleration (g = 9.8) m Bomb weight V Bomb size <![CDATA[ρ1]]> Bomb Density <![CDATA[ρ2]]> Seawater density H The aircraft's flight altitude h Submarine diving depth

[0034] Example

[0035] In this embodiment, the specific diving depth of the submarine is not determined, but only a rough range (within 20-60m) is given. To determine the best time to drop the bomb, two aspects need to be considered: first, when the measured diving depth of the submarine has a certain error, it will cause the impact point of the bomb to deviate, and we try to minimize the deviation of the impact point; secondly, considering the length and width of the submarine, in order to hit the submarine as much as possible without hitting the center of the submarine, it is necessary to analyze the necessary and sufficient conditions for the submarine to be hit, so as to determine the best time to drop the bomb.

[0036] First calculate the time the bomb is in the air. List the velocity component equations for the bomb:

[0037]

[0038] The curve equation of the bomb's motion is:

[0039]

[0040] Target speed equation:

[0041]

[0042] The target curve equation is:

[0043]

[0044] From the curve equation of the bomb motion and the curve equation of the target, we can get:

[0045]

[0046] In the curve equation of the bomb's motion, z = 0, which gives the time the bomb spends in the air.

[0047]

[0048] Obviously, the bomb can hit the target when the x and y coordinates of the bomb and the target are equal.

[0049] When the submarine is at a depth of h, the bomb can hit the center of the submarine (x0, y0). The time it takes for the bomb to arrive is:

[0050]

[0051] When the submarine's depth has an error of Δh, that is, the depth is (h+Δh), the bomb flight time is:

[0052]

[0053] Let ΔT2=T2(h+Δh)-T2(h)

[0054]

[0055] From the equation of the bomb's flight curve, we can know that the coordinates of the position where the bomb hits the submarine are:

[0056]

[0057] The initial coordinates of this position at the moment the plane launches the bomb should be:

[0058]

[0059] The error is

[0060]

[0061] Leaving the center position Obviously, when Δh is small and constant, The smaller the better, considering Δh→0, that is The smaller the better.

[0062] From the derivative rule of composite function, we know:

[0063]

[0064] so and

[0065]

[0066]

[0067] Similarly, we can get:

[0068]

[0069] but:

[0070]

[0071] Obviously, when h is smaller, The smaller.

[0072] On the other hand, the plane coordinate system is rotated and transformed into Figure 2 As shown:

[0073] Then there is Right now When there is a change (Δx, Δy) in the xoy plane coordinate system, the coordinates of this point in x′oy′ are (Δxcosγ+Δysinγ,-Δxsinγ+Δycosγ). In order for the bomb to still hit the submarine, then:

[0074]

[0075] Combining the above formula, we get:

[0076]

[0077] Combining formulas

[0078]

[0079] Right now:

[0080]

[0081] Simplified:

[0082]

[0083] To sum up, under the premise of satisfying the above conditions, the smaller the depth h of the submarine is, the better.

[0084] For example, when the direction of the aircraft is consistent with the direction of the wind and the submarine is along the negative direction of the y-axis (opposite to the direction of the aircraft), then: x = 0, α = 90°, β = 90°, γ = 180°, and we get:

[0085] y0-(v2+v3)T2=v1T2

[0086] Right now:

[0087] y0=(v1+v2+v3)T2

[0088] and

[0089]

[0090] The error is:

[0091]

[0092] because and Compared with H = 1000, it is very small, then:

[0093]

[0094] When 20≤h≤40, the maximum value of Δh is 60-h, so Δy≤50 is equivalent to 1.6984(60-h)≤

[0095] 50, so h ≥ 30.56.

[0096] When 40≤h≤60, the maximum value of Δh is h-20, so Δy≤50 is equivalent to 1.6984(h-20)≤50, so h≤49.44.

[0097] From the conclusions stated above, we know that when the submarine depth is h=30.56, the best time to drop bombs is when y0=237.78×14.5005=3448 meters, that is, the best time to drop bombs is when the horizontal distance between the aircraft and the submarine is 3448 meters.

[0098] The present invention has the following beneficial effects:

[0099] The modeling idea of ​​the present invention is clear, the method of establishing the model is relatively simple and easy to understand; the established models are all given in mathematical formulas and are easy to promote.

[0100] As used herein, the word "preferred" is intended to be used as an example, instance, or illustration. Any aspect or design described herein as "preferred" is not necessarily to be construed as being more advantageous than other aspects or designs. On the contrary, the use of the word "preferred" is intended to present concepts in a specific way. The term "or" as used in this application is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or clear from the context, "X uses A or B" means any one of the naturally included permutations. That is, if X uses A; X uses B; or X uses both A and B, then "X uses A or B" is satisfied in any of the foregoing examples.

[0101] Moreover, although the present disclosure has been shown and described with respect to one or implementations, those skilled in the art will think of equivalent variations and modifications based on the reading and understanding of this specification and the accompanying drawings. The present disclosure includes all such modifications and variations, and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the above-mentioned components (such as elements, etc.), the terms used to describe such components are intended to correspond to any component (unless otherwise indicated) that performs the specified function of the component (such as it is functionally equivalent), even if the structure is not equivalent to the disclosed structure of the function in the exemplary implementation of the present disclosure shown herein. In addition, although the specific features of the present disclosure have been disclosed with respect to only one of several implementations, such features can be combined with one or other features of other implementations that may be desired and advantageous for a given or specific application. Moreover, insofar as the terms "including", "having", "containing" or their variations are used in specific embodiments or claims, such terms are intended to be included in a manner similar to the term "comprising".

[0102] The functional units in the embodiments of the present invention may be integrated into a processing module, or each unit may exist physically separately, or multiple or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium. The above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc. The above-mentioned devices or systems may execute the storage method in the corresponding method embodiment.

[0103] To sum up, the above embodiment is an implementation mode of the present invention, but the implementation mode of the present invention is not limited by the embodiment. Any other changes, modifications, substitutions, combinations, and simplifications that deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for delivering an object based on the positional relationship between an aircraft and a submerged object, characterized in that: The following steps are involved: When the submarine's depth is h, the flight time of the bomb hitting the center of the submarine (x0, y0) is: Where ρ1 is the density of the bomb, ρ2 is the density of seawater, H is the height of the aircraft from the sea surface, and g is the acceleration due to gravity; When the submarine's depth has an error of Δh, that is, the depth is (h+Δh), the bomb flight time is: Let ΔT2=T2(h+Δh)-T2(h) From the equation of the bomb's flight curve, we can know that the coordinates of the position where the bomb hits the submarine are: v1 is the initial velocity of the bomb, v2 is the wind speed, α is the angle between the wind and the x-axis, and β is the angle between the bomb launch direction and the x-axis; The initial coordinates of this position at the moment the plane launches the bomb should be: γ is the angle between the target's moving direction and the y-axis, and v3 is the target's velocity; The error is Leaving the center position have When there is a change (Δx, Δy) in the xoy plane coordinate system, the coordinates of this point in x′oy′ are (Δxcosγ+Δysinγ,-Δxsinγ+Δycosγ). In order for the bomb to still hit the submarine, then:

2. The object delivery method based on the positional relationship between an aircraft and a submerged object according to claim 1, characterized in that: Consider Δh→0, that is The smaller the better. From the derivative rule of composite function, we know: so and Similarly, we can get: but: When h is smaller, The smaller.

3. The object delivery method based on the positional relationship between an aircraft and a submerged object according to claim 1, characterized in that: When the direction of the aircraft is consistent with the direction of the wind and the submarine is along the negative direction of the y-axis, x=0, α=90°, β=90°, γ=180°: y0=(v1+v2+v3)T2 and The error is: because and is very small compared to H, then: When 20≤h≤40, the maximum value of Δh is 60-h, h≥30.56; When 40≤h≤60, the maximum value of Δh is h-20, h≤49.44.

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