Fine correction method for ship gun firing data under composite disturbance

Abstract

The invention discloses a ship gun firing data fine correction method under composite disturbance, and provides a ship gun firing data fine correction method under comprehensive consideration of ship attitude and muzzle projectile initial velocity influence aiming at the problem that a ship gun fire control system is low in combat hit precision under a composite disturbance environment. The iteration amount is updated by calculating the hit point deviation amount, so that the iteration efficiency is improved; the method comprises the following steps: firstly, establishing a shooting model under composite disturbance of a ship gun, and converting a ship navigation speed, a ship gun follow-up motion involved speed and an additional speed generated by ship swinging to a muzzle projectile; correcting the initial velocity of the projectile under composite disturbance by using a vector superposition method, introducing the corrected initial velocity of the projectile into a solving process of a hit equation set, and adjusting the firing angle of the ship gun according to the posture of the ship; finally, the simulation result verifies that the method can effectively improve the target shooting precision and hit probability of the ship artillery fire control system.

Description

Technical Field

[0001] The invention belongs to the technical field of naval gun fire control systems, and in particular relates to a method for fine correction of naval gun firing parameters under composite disturbances. Background Art

[0002] When shipborne artillery is performing missions at sea, it is inevitably affected by external disturbances such as wind and waves, which causes the ship to produce composite disturbances such as swaying, slamming, rising and sinking on the sea level. This complex and changeable environment will not only change the attitude of the ship; but also make the initial velocity of the projectile affected by the ship's sailing speed, the speed involved in the follow-up motion of the ship's gun, and the additional velocity generated by the ship's swaying, which will cause the projectile's outer ballistic trajectory to deviate from the ideal trajectory, and ultimately increase the projectile-target deviation. Therefore, in order to improve the accuracy of shipborne artillery, it is necessary to correct the initial velocity of the projectile under composite disturbances and introduce the corrected initial velocity of the projectile into the solution of the hit equation group. At the same time, the firing angle of the ship's gun is adjusted according to the attitude of the ship to ensure that the ship's gun maintains a high hit accuracy under complex sea levels.

[0003] At present, the method of calculating the hit parameters based on the firing table is to treat the relative muzzle velocity of the projectile as the ballistic meteorological correction, in which the change in the initial velocity of the projectile in the actual naval gun barrel relative to the initial velocity specified in the firing table is corrected, and the movement of the ship is converted into the meteorological correction as the sailing wind for correction. This method does not consider the other various effects of the projectile on the exit velocity of the barrel when correcting the ship's movement. In addition, the method of calculating the hit parameters based on the ballistic differential equation usually only considers the correction of the initial velocity of the projectile by the translational motion of the ship, while the influence of the implicated motion disturbance caused by the follow-up of the naval gun and the motion disturbance of the ship in the complex sea level posture on the initial velocity of the projectile is rarely considered, which cannot further effectively improve the final hit accuracy of the naval gun. Summary of the invention

[0004] The present invention proposes a method for fine correction of various parameters of naval gun firing under compound disturbance, which corrects the muzzle projectile initial velocity under compound disturbance, introduces the corrected projectile initial velocity into the solution of the hit parameter equation group, and then adjusts the azimuth and elevation angle of naval gun firing according to the ship's attitude. This method can enable naval guns to obtain more accurate firing parameters under compound disturbance, and improve the hit accuracy of naval gun fire control systems under compound disturbance.

[0005] The technical solution to achieve the purpose of the present invention is: a method for fine correction of various parameters of naval gun firing under composite disturbance, comprising the following steps:

[0006] Step 1: Establish a set of hit equations based on the projectile mass equation and the target position in the geographic reference coordinate system, and use an iterative method to solve the azimuth, elevation and flight time of the naval gun;

[0007] Step 2: Under the combined disturbance, convert the entrained velocity of the shipboard gun's follow-up motion and the additional velocity generated by the ship's swaying motion to the muzzle of the shipboard gun;

[0008] Step 3: Unify the coordinate system, correct the muzzle velocity of the projectile by the vector superposition method. The corrected muzzle velocity of the projectile is the vector sum of the ship's navigation speed, the entrained velocity of the shipboard gun's follow-up motion, and the additional velocity generated by the ship's swaying motion; introduce the corrected muzzle velocity into the hit element equations, solve the corrected firing elements by the iterative method, and adjust the elevation angle of the shipboard gun according to the ship's attitude.

[0009] A computer device includes a memory, a processor, and a computer program that can run on the memory and on the processor. When the processor executes the program, the steps of the above method are implemented.

[0010] A computer-readable storage medium stores a computer program thereon. When the program is executed by a processor, the steps of the above method are implemented.

[0011] A computer program product includes a computer program. When the computer program is executed by a processor, the steps of the above method are implemented.

[0012] Compared with the prior art, the remarkable advantages of the present invention are as follows: Based on the traditional iterative method, the iteration amount is updated by calculating the deviation amount of the hit point, thereby improving the iteration efficiency. Further, the influence of the ship's own speed, the entrained velocity caused by the shipboard gun's follow-up motion, the additional velocity generated by the ship's swaying, and the ship's attitude on the shooting accuracy of the shipboard gun is considered. By introducing the corrected muzzle velocity of the projectile into the hit element equations and adjusting the elevation angle of the shipboard gun according to the ship's attitude, this method effectively corrects the firing elements of the shipboard gun and improves the hit accuracy of the shipboard gun fire control system in a complex environment. Description of the Drawings

[0013] Figure 1 It is the iterative flow chart for solving the hit elements.

[0014] Figure 2 It is the rotation transformation diagram of the ship's geographic reference system.

[0015] Figure 3 It is the ship's roll model diagram.

[0016] Figure 4 It is the decomposition diagram of the additional velocity generated by the ship's roll on the muzzle projectile.

[0017] Figure 5 It is the ship's pitch model diagram.

[0018] Figure 6 It is the decomposition diagram of the additional velocity generated by the ship's pitch on the muzzle projectile.

[0019] Figure 7It is a model diagram of the yaw of a ship's bow.

[0020] Figure 8 It is a decomposition diagram of the additional velocity generated by the yaw of a ship's bow on the muzzle projectile.

[0021] Figure 9 It is a model diagram of the follow-up movement of a naval gun.

[0022] Figure 10 It is a decomposition diagram of the transport velocity of the muzzle projectile caused by the follow-up movement of a naval gun.

[0023] Figure 11 It is a distribution diagram of projectile impact points.

[0024] Figure 12 It is a schematic diagram of the hit probability of a projectile. Specific implementation manner

[0025] The present invention proposes a method for finely correcting the firing elements of a naval gun under combined disturbances, mainly including the establishment of a hit element equation set, and converting the transport velocity of the follow-up movement of the naval gun and the additional velocity generated by the ship's swaying movement to the muzzle of the naval gun under combined disturbances; after unifying the coordinate systems, the initial velocity of the projectile is corrected by the vector superposition method, and the corrected initial velocity of the projectile is the vector sum of the ship's navigation speed, the transport velocity of the follow-up movement of the naval gun, and the additional velocity generated by the ship's swaying movement; then the corrected initial velocity of the projectile is introduced into the hit element equation set, and the firing elements of the naval gun are solved by the iterative method, and finally the firing azimuth and elevation angles of the naval gun are adjusted according to the ship's attitude.

[0026] The following combines the attached Figure 1 , and details the specific steps of the present invention.

[0027] A method for finely correcting the firing elements of a naval gun under combined disturbances includes the following steps:

[0028] Step 1, establish a hit element equation set according to the projectile mass point equation and the target position in the geographical reference coordinate system, and use the iterative method to solve the azimuth angle, elevation angle and flight time of the naval gun;

[0029] Define the initial velocity of the projectile as v, the air resistance suffered by the projectile during flight as F, and the gravitational acceleration as g, then the force equation of the projectile can be expressed as:

[0030]

[0031] Assume that the resistance acceleration suffered by the projectile is a, and according to Newton's law, further deduce the force equation of the projectile to obtain:

[0032]

[0033] Define x, y, z as the components of the projectile position on the X, Y, Z axes; vx , v y , v z are the velocity components of the projectile initial velocity v along the X, Y, and Z axes; a x , a y , a z are the velocity components of the projectile drag acceleration a along the X, Y, and Z axes; the ballistic coefficient is C, the air density function is H, and the drag coefficient is G; projecting the vector equation onto the OX axis, OY axis, and OZ axis respectively, the differential equations of the particle trajectory can be obtained as follows:

[0034]

[0035] Define point O as the muzzle position of the naval gun. The position of the target current point at the zero moment is M, and the position of the target future point predicted at time t k is M q . These three points together form the naval gun hit vector triangle, which can be represented by vectors as:

[0036] OM q = OM + MM q

[0037] Define the position of the target future point at time t k as M q . The position, velocity, and acceleration of the target at the zero moment are M(0) = [x m , y m , z m , V(0) = [v mx , v my , v mz , A(0) = [a mx , a my , a mz . Then the position coordinates of the target at time t k M q (t k ) = [x q (t k ), y q (t k ), z q (t k )] can be expressed as:

[0038]

[0039] Define the included angle between OM and MM q as α, and the projectile initial velocity as v0. Then the naval gun hit vector triangle OMM q satisfies the following relationship:

[0040]

[0041] According to the shipboard gun hit space vector triangle OMM q and the cosine law, the flight time t q of the projectile hitting the target point M k can be solved.

[0042] Define the azimuth angle and elevation angle of shipboard gun firing as β0 and ε0 respectively. Then, based on the position of the hit point, the firing azimuth angle and elevation angle of the shipboard gun can be preliminarily calculated as follows:

[0043]

[0044] Define the deviation of shipboard gun firing data D i as the distance between the projectile hit point and the actual target position at time t i during the i-th iteration process. Based on the deviation D i , the firing data can be continuously iterated and corrected until the firing accuracy is satisfied. Taking the zeroth iteration as an example, on the basis of determining the initial iteration values (t0, β0, ε0), substituting them into the projectile particle differential equation system and integrating the region (0, t0) can obtain the projectile hit position as M c [(x c (t0), y c (t0), z c (t0)]. Then, the hit position deviation can be expressed as:

[0045]

[0046] Define (Δk i , Δβ i , Δε i ) as the deviation of the projectile flight time, elevation angle, and flight time respectively. Then, the deviation of the firing data between the first hit position and the actual target position can be expressed as:

[0047]

[0048] Taking the deviation result as the correction amount of the firing data, substituting the obtained correction amount of the firing data into the initial iteration values (t0, β0, ε0), the first iteration firing data (t1, β1, ε1) can be obtained. The specific process is as Figure 1 shown. When the difference between the projectile hit point and the target position does not meet the hit accuracy, the correction amount of the firing data will be recalculated and the iteration will continue until the i-th iteration meets the hit accuracy. At this time, the firing data is [t i , β i , ε i . The shipboard gun hit data equation system can be simplified as:

[0049]

[0050] The influence of compound disturbances on the muzzle velocity of the projectile includes the ship's navigation speed, the tangential speed of the gun's follow-up movement, and the additional speed generated by the ship's rolling motion. The corrected muzzle velocity of the projectile is the result of the vector superposition of the projectile's muzzle velocity relative to the gun barrel, the ship's navigation speed, the tangential speed of the gun's follow-up movement, and the additional speed of the ship's rolling.

[0051] Step 2: Convert the tangential speed of the gun's follow-up movement and the additional speed generated by the ship's rolling motion to the gun muzzle under compound disturbances, which specifically includes the following steps:

[0052] Step 1: The muzzle velocity of the projectile relative to the gun barrel, v0, can be measured by a velocity measuring radar installed on the gun barrel;

[0053] Step 2: The ship's navigation speed, v, can be measured by the ship's inertial navigation system or satellite positioning system c ;

[0054] Step 3: Define O-X w Y w Z w as the ship's geographical reference system, which takes the center of the ship's roll or a certain point on the ship as the origin. The X w axis is along the tangent of the origin's latitude, with the direction pointing east; the Y w axis is along the tangent of the origin's longitude, with the direction pointing north; the Z w axis is perpendicular to the horizontal plane where the origin is located, pointing towards the zenith. The ship's geographical reference system O-X w Y w Z w can be rotated three times around the origin to obtain an unstable ship reference system O-X b Y b Z b , and the specific process is as Figure 2 shown: For the first rotation, the ship's geographical reference system O-X w Y w Z w rotates around the OZ w axis by C w to form the reference system O-X1Y1Z w ; for the second rotation, the reference system O-X1Y1Z w rotates around the OX1 axis by ψ to form the reference system O-X1Y2Z2; for the third rotation, the reference system O-X1Y2Z2 rotates around the OY1 axis by θ b to obtain the unstable ship reference system O-X b Y b Z b .

[0055] Define O-X wpg Y wpg Z wpgis the ship gun geographical reference system. The three reference axes of the ship gun geographical reference system are consistent with those of the ship geographical reference system. They are not fixed to the ship and will not sway with the ship. Only the origin of the reference system is located at the center of rotation of the ship gun, while the reference origin of the ship geographical reference system is at the center of sway of the ship. The ship gun geographical reference system O-X wpg Y wpg Z wpg Similar to the ship geographical reference system, rotating three times around the origin can also obtain an unstable ship gun reference system O-X pg Y pg Z pg .

[0056] Step4: The roll angle θ w Y w Z w of the ship relative to the ship geographical reference system O-X b , pitch angle ψ, and yaw angle C w as well as the corresponding angular velocities w θ , w ψ , w cw can be measured by an attitude sensor or a gyroscope. Denote the azimuth angle of the ship gun under the combined disturbance as β, the elevation angle as ε, and the length of the gun barrel as d. Then the position coordinates of the muzzle point P in the unstable ship gun reference system are:

[0057]

[0058] Assume that the position of the center of rotation O pg of the gun barrel in the unstable ship reference system is (x yb_0 , y yb_0 , z yb_0 ). Since the three coordinate axes of the unstable ship gun reference system and the unstable ship reference system point in the same direction, the position of the muzzle point P in the unstable ship reference system can be obtained through translation transformation as:

[0059]

[0060] As Figure 3 shown, when the ship rolls, it actually swings around the axis OY w . Then the distance L hy from the muzzle point P to the roll axis is:

[0061]

[0062] Define the additional velocity generated by the ship's roll on the muzzle as v θ . The velocity obtained by converting the angular velocity of the ship's roll to the muzzle is:

[0063] v θ = w θL hy

[0064] like Figure 4 As shown, the OP line and the unstable reference axis OX when the ship rolls are defined b The angle is Then the muzzle position P can be obtained:

[0065]

[0066] The additional velocity v generated by the ship's rolling on the muzzle projectile θ The projection in the unstable ship reference system is:

[0067]

[0068] like Figure 5 As shown in the figure, when the ship pitches, it actually rolls around the pitch axis OX w Swing, so the distance L between the muzzle P and the pitch axis zy for:

[0069]

[0070] The additional velocity caused by the ship's pitching on the muzzle is defined as v ψ , the angular velocity of the ship's pitch is converted to the velocity at the muzzle:

[0071] v ψ =w ψ L zy

[0072] like Figure 6 As shown, the OP line and the unstable reference axis OY when the ship pitches are defined b The angle is γ, then the muzzle position P can be obtained:

[0073]

[0074] The additional velocity v of the muzzle projectile caused by the ship's pitch ψ The projection in the unstable ship reference system is:

[0075]

[0076] like Figure 7 As shown in Figure 2, when a ship pitches forward, it actually moves around the axis OZ w Swing, so the distance L between the muzzle P and the bow axis sy for:

[0077]

[0078] Define the additional velocity generated by the yaw of the ship at the muzzle as v cw , and the linear velocity obtained by converting the angular velocity of the ship's yaw to the muzzle projectile is:

[0079] v cw = w cw L zy

[0080] As Figure 8 shown, define the angle between the OP line and the unstable reference frame axis OX b during the ship's yaw as λ. Then, the position of point P at the muzzle can be used to obtain:

[0081]

[0082] The additional velocity v of the muzzle projectile caused by the ship's yaw cw The projection component in the unstable ship reference frame is:

[0083]

[0084] Define v ybx , v yby , v ybz as the additional velocity v generated by the ship's sway yb The velocity projection in the unstable ship reference frame O-X b Y b Z b Then, the projection component of the additional velocity generated by the ship's sway on the muzzle projectile is:

[0085]

[0086] Step5: Define v s as the transport velocity caused by the follow-up movement of the naval gun at the muzzle. It can be regarded as the result of the combined action of the movement of the gun barrel in the azimuth and elevation directions. As Figure 9 , Figure 10 shown. Denote v sβ as the transport velocity of the gun barrel in the azimuth direction, and v sε as the transport velocity of the gun barrel in the elevation direction. In the unstable reference frame O-X pg Y pg Z pg of the naval gun, the length of the gun barrel is d. Assume that the azimuth angular velocity of the naval gun barrel is w β , and the elevation angular velocity is w ε . Then, the transport velocity converted to the muzzle is:

[0087] v sβ = w β dcosβ

[0088] v sε = wε d

[0089] Define v sβx , v sβy be the projection components of v sβ in the unstable naval gun reference system X pg , Y pg , Z pg respectively. Then we can get:

[0090]

[0091] Define v sεx , v sεy , v sεz be the projection components of v ε on the X pg , Y pg , Z pg axis of the unstable naval gun reference system respectively. Then we can get:

[0092]

[0093] Define v sx , v sy , v sz be the convective velocity v s caused by the follow-up motion of the naval gun at the muzzle in the unstable naval gun reference system X pg , Y pg , Z pg respectively. Then the convective velocity caused by the follow-up motion of the naval gun at the muzzle is the result of the vector superposition of the barrel in the azimuth and elevation directions:

[0094]

[0095] Step6: Since the three reference axes of the unstable naval gun reference system and the unstable ship reference system have the same direction, only the reference origin is different. Here, the convective velocity vector v s caused by the follow-up motion of the naval gun in the unstable naval gun reference system is transformed to the unstable ship reference system through translation.

[0096] Define v h as the influence on the initial velocity of the projectile at the muzzle under the combined disturbance. To sum up, the action result of the combined disturbance on the initial velocity of the projectile at the muzzle is:

[0097] v h = v c + v s + v yb .

[0098] Step 3: Unify the coordinate system and correct the initial velocity of the projectile by the vector superposition method. The corrected initial velocity of the projectile is the sum of the ship's navigation speed, the entrainment speed of the shipboard gun's follow-up movement, and the additional velocity vectors generated by the ship's swaying movement. Introduce the corrected initial velocity of the projectile into the hit element equations, and use the iterative method to solve the corrected firing elements. Adjust the elevation angle of the shipboard gun according to the ship's attitude, as follows:

[0099] Define the corrected initial velocity of the projectile under the combined disturbance as v he , then the corrected initial velocity of the projectile in the unstable ship reference system is:

[0100] v he = v0 + v h

[0101] Define the corrected initial velocity of the projectile in the ship's geographical reference system as v d . According to the coordinate transformation principle, transform the corrected initial velocity of the projectile from the unstable ship reference system to the ship's geographical reference system, and the corrected initial velocity of the projectile in the ship's geographical reference is obtained as:

[0102]

[0103] Define v dx , v dy , v dz as the projection velocity components of the corrected initial velocity v d of the projectile in the ship's geographical reference system O-X w Y w Z w . Then the hit element equations after correcting the initial velocity of the projectile under the combined disturbance are:

[0104]

[0105] Define Δβ(t), Δε(t), ΔT(t) as the correction amounts of the shipboard gun firing elements under the combined disturbance; under the combined disturbance, the firing azimuth angle of the shipboard gun before correcting the initial velocity of the projectile is β r , the elevation angle is ε r , and the flight time is T r ; the firing azimuth angle of the shipboard gun after correction is β d , the elevation angle is ε d , and the flight time is T d . Then the correction amounts of the shipboard gun firing elements are:

[0106]

[0107] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0108] Embodiment

[0109] Under standard meteorological conditions, a certain shipborne gun performs combat missions at sea level. The initial velocity of the shipborne gun projectile is 980 m / s, the total mass of the projectile is 1.2 kg, the projectile body diameter is 0.057 m, the gun barrel length is 2.4 m, and the ballistic coefficient i is 0.36. When striking a target under combined disturbances, the radar measures the ship's own speed to be 40 km / h. The gyroscopic tachometer measures the azimuth angular velocity of the gun barrel at this time to be 0.087 rad / s, the pitch angular velocity to be 0.0052 rad / s, the roll, pitch, and yaw angles of the ship are all 10°, the roll angular velocity of the ship is 0.0174 rad / s, the pitch angular velocity of the ship is 0.087 rad / s, and the yaw angular velocity of the ship is 0.0174 rad / s. The position of the gun barrel's rotation center in the unstable ship reference system is [10, 12, 15]. Assume that there is a 2×2 circular vertical target regarded as the target on the sea level, and its coordinate position is [0, 3000, 10].

[0110] When determining the position of the target, according to the firing data equations, the firing azimuth angle and pitch angle of the shipborne gun can be obtained by the iterative method. According to this firing angle, the projectile fired by the shipborne gun can hit the center point of the circular target surface under ideal conditions. However, under combined disturbances, the initial velocity of the projectile at the moment of firing will change, which will cause the projectile to deviate from the predetermined trajectory and ultimately lead to the deviation between the projectile and the target. According to the above parameters, the deviation between the projectile and the target under combined disturbances is 1.727 m.

[0111] To evaluate the hit rate of the shipborne gun, in engineering practice, a large number of firing experiments are usually used to analyze the distribution of the hitting points of the projectiles on the vertical target. When the projectile hits the circular vertical target, it is regarded as hitting the target, and the ratio of the number of projectile hits to the total number of firings is statistically analyzed to evaluate the hit rate of the shipborne gun. Monte Carlo simulation is a calculation method based on random sampling, which is used to simulate and evaluate the uncertainty and risk of various complex systems or processes. After multiple repeated simulations, statistical analysis of the results is carried out to obtain a reliable estimate of the system performance. In engineering, Monte Carlo simulation is often used to simulate the hit rate of shipborne gun projectiles. Using the Monte Carlo simulation method, 1000 hitting simulations were carried out on the projectiles before and after the initial velocity correction. The distribution of the hitting points of the projectiles on the projectile-facing surface is as Figure 11 shown.

[0112] Before the initial velocity correction, due to the interference of various factors such as combined disturbances and random errors, most of the hitting points of the projectiles are distributed outside the circular target surface and are far from the target center. After correction, the positions of the hitting points of the projectiles are more concentrated within the circular target surface.

[0113] As Figure 12 shown, by statistically analyzing the distribution of the projectiles on the projectile-facing surface in the Monte Carlo simulation, considering the projectiles within a distance less than 2 m as hitting the target, after correcting the initial velocity of the projectile under combined disturbances, the hit probability of the shipborne gun increases from 50.5% to 81.3%.

[0114] Table 1 Gun Firing Data

[0115]

[0116] As shown in Table 1, considering the influence of compound disturbances on gun firing data and introducing it into the solution of the hit data equations, the azimuth angle, elevation angle, and flight time of the gun firing at a stationary target after correction are all reduced. This method helps the gun obtain more accurate firing data during combat in complex environments, thus improving the firing accuracy of the gun at stationary targets.

[0117] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A method for fine correction of various parameters of naval gun firing under composite disturbance, characterized in that: The following steps are involved: Step 1: Establish a set of hit equations based on the projectile mass equation and the target position in the geographic reference coordinate system, and use an iterative method to solve the azimuth, elevation and flight time of the naval gun; Step 2, under the composite disturbance, convert the velocity involved in the naval gun's following motion and the additional velocity generated by the ship's swaying motion to the naval gun's muzzle; Step 3, unify the coordinate system and correct the initial velocity of the projectile by vector superposition method. The corrected initial velocity of the projectile is the sum of the ship's navigation speed, the velocity involved in the follow-up motion of the ship's gun, and the additional velocity vector generated by the ship's swaying motion; introduce the corrected initial velocity of the projectile into the hit equation group, use the iterative method to solve the corrected shooting parameters, and adjust the firing angle of the ship's gun according to the ship's posture.

2. The method for fine correction of various parameters of naval gun firing under composite disturbance according to claim 1 is characterized in that: Step 1: Establish the hit equations according to the projectile mass equation and the target position in the geographic reference coordinate system, and use the iterative method to solve the azimuth, elevation and flight time of the naval gun, specifically: Define the initial velocity of the projectile as v, the mass of the projectile as m, the air resistance of the projectile in flight as F, and the acceleration of gravity as g, then the force equation of the projectile can be expressed as: Assuming that the resistance acceleration of the projectile is a, according to Newton's law, the force equation of the projectile can be further deduced to obtain: Define x, y, z as the components of the projectile position on the X, Y, and Z axes; v x ,v y ,v z are the velocity components of the projectile's initial velocity v on the X, Y, and Z axes respectively; a x ,a y ,a z are the velocity components of the projectile drag acceleration a on the X, Y, and Z axes respectively; the ballistic coefficient is C, the air density function is H, and the drag coefficient is G; projecting the vector equation to the OX axis, OY axis, and OZ axis respectively, the particle trajectory differential equation can be obtained as follows: Define point O as the muzzle position of the ship's gun, the current position of the target at time zero is M, and at t k The future point position of the target is predicted to be M at the moment q , these three points together form the gun hit vector triangle, which can be expressed as: IF q =OM+MM q Definition k The future position of the target point at the moment is M q , the target position, velocity and acceleration at time zero are M(0)=[x m ,y m ,z m ],V(0)=[v mx ,v my ,v mz ],A(0)=[a mx ,a my ,a mz ], then t k The target's position coordinates at the moment M q (t k )=[x q (t k ),y q (t k ),z q (t k )] can be expressed as: Defining OM and MM q The angle between them is α, and the initial velocity of the projectile is v0, then the naval gun hits the vector triangle OMM q Satisfies the following relationship: According to the space vector triangle OMM of the naval gun hit q The cosine law solves the projectile hitting the target point M q The flight time t k ; Define the azimuth and elevation of the gun firing as β0 and ε0 respectively. Then, based on the position of the hit point, the azimuth and elevation of the gun firing are preliminarily calculated as follows: Definition of the deviation of the firing parameters of naval guns D i is the number of iterations in t i The distance between the projectile impact point and the actual target position at the moment, based on D i The deviation is continued to iterate and the shooting parameters are continuously corrected until the shooting accuracy is met; for the zeroth iteration, on the basis of determining the initial value of the iteration (t0, β0, ε0), it is substituted into the differential equation group of the projectile particle and integrated over the area (0, t0) to obtain the projectile hit position M c [(x c (t0),y c (t0),z c (t0)], the hit position deviation can be expressed as: Definition (Δk i ,Δβ i ,Δε i ) are the deviations of the projectile flight time, pitch angle and flight time respectively, then the deviation of the shooting elements between the first hit position and the actual target position is expressed as: The deviation result is used as the correction value of the shooting parameters, and the obtained correction values ​​are substituted into the initial value of the iteration (t0, β0, ε0), that is, the shooting parameters of the first iteration (t1, β1, ε1) are obtained; when the difference between the projectile impact point and the target position does not meet the hit accuracy, the correction value of the shooting parameters will be recalculated, and the iteration will continue until the i-th iteration meets the hit accuracy. At this time, the shooting parameters are [t i ,β i ,ε i ]; The equations of various variables for naval gun hit can be simplified to: The influences on the initial velocity of the projectile under the composite disturbance include the ship's navigation speed, the velocity involved in the gun's following motion, and the additional velocity caused by the ship's swaying motion. The corrected initial velocity of the projectile is the result of the vector superposition of the projectile's relative barrel velocity, the ship's navigation speed, the velocity involved in the gun's following motion, and the additional velocity generated by the ship's swaying motion.

3. The method for fine correction of various parameters of naval gun firing under composite disturbance according to claim 2 is characterized in that: Step 2: Under the composite disturbance, the velocity involved in the gun's following motion and the additional velocity generated by the ship's swaying motion are converted to the gun's muzzle, specifically: Step 1: The initial velocity of the projectile relative to the barrel is measured by the velocity radar installed on the barrel, which is v0; Step 2: Measure the ship's speed v through the ship's inertial navigation system or satellite positioning system c ; Step 3: Define OX w Y w Z w is the ship's geographic reference system, which takes the ship's sway center as the origin, X w The axis is the tangent line along the origin latitude, pointing eastward; w The axis is the tangent to the meridian of the origin, pointing north; Z w The horizontal plane where the axis is vertically located and points to the zenith; the ship's geographic reference system OX w Y w Z w Rotating around the origin three times can obtain an unstable ship reference system OX with a common origin. b Y b Z b , first rotation, ship geographic reference system OX w Y w Z w Around OZ w Axis rotation C w After that, the reference system O-X1Y1Z is formed w ; Second rotation, reference system O-X1Y1Z w After rotating ψ around the OX1 axis, the reference system O-X1Y2Z2 is formed; the third rotation, the reference system O-X1Y2Z2 rotates θ around the OY1 axis b After that, the unstable ship reference system OX is obtained b Y b Z b ; Defining OX wpg Y wpg Z wpg The three reference axes of the naval gun geographic reference system are consistent with the ship geographic reference system. They are not fixed to the ship and will not swing with the ship. The origin of the reference system is located at the rotation center of the naval gun, while the origin of the ship geographic reference system is at the swing center of the ship. The naval gun geographic reference system OX wpg Y wpg Z wpg Like the ship's geographic reference system, rotating three times around the origin can also obtain an unstable ship gun reference system OX with a common origin. pg Y pg Z pg ; Step 4: The ship is relative to the ship's geographic reference system OX under the composite disturbance w Y w Z w The roll angle θ b , pitch angle ψ, bow angle C w And the corresponding angular velocity w θ ,w ψ ,w cw It is measured by attitude sensor or gyroscope, and the azimuth angle β of the gun under the composite disturbance is recorded as ε, the pitch angle is ε, and the length of the gun barrel is d. Then the position coordinates of the muzzle point P in the unstable gun reference system are: Assume that the barrel rotation center is O pg The position of the unstable ship reference system is (x yb_0 ,y yb_0 ,z yb_0 ), since the three coordinate axes of the unstable gun reference system and the unstable ship reference system point in the same direction, the position of the muzzle position point P in the unstable ship reference system can be obtained by translation transformation as: When a ship rolls, it is actually rolling around the axis OY. w Swing, then the distance L between the muzzle point P and the roll axis hy for: Define the additional velocity of the ship's rolling on the muzzle as v θ , the angular velocity of the ship's roll is converted to the velocity at the muzzle: v θ =w θ L hy Define the OP line and the unstable reference axis OX when the ship rolls b The angle is Then the muzzle position P can be obtained: The additional velocity v generated by the ship's rolling on the muzzle projectile θ The projection in the unstable ship reference system is: When a ship pitches, it actually rolls around the pitch axis OX w Swing, so the distance L between the muzzle P and the pitch axis zy for: The additional velocity caused by the ship's pitching on the muzzle is defined as v ψ , the angular velocity of the ship's pitch is converted to the velocity at the muzzle: v ψ =w ψ L zy Define the OP line and the unstable reference axis OY when the ship pitches b The angle is γ, then the muzzle position P can be obtained: The additional velocity v of the muzzle projectile caused by the ship's pitch ψ The projection in the unstable ship reference system is: When a ship pitches forward, it is actually moving around the axis OZ w Swing, so the distance L between the muzzle P and the bow axis sy for: Define the additional velocity caused by the ship's bow rolling on the muzzle as v cw , the angular velocity of the ship's bow is converted to the linear velocity of the projectile at the muzzle: v cw =w cw L zy Define the connection between OP and the unstable reference axis OX when the ship pitches forward b The angle is λ, then the muzzle position P can be obtained: The additional velocity v of the muzzle projectile caused by the ship's bow pitch cw The projected components in the unstable ship reference system are: Define v ybx ,v yby ,v ybz The additional velocity v generated by the ship's rolling yb In the unstable ship reference system OX b Y b Z b The additional velocity projection component of the ship's swing on the muzzle projectile is: Step 5: Define v s is the velocity of the gun at the muzzle caused by the gun's follow-up motion, denoted by v sβ is the velocity of the gun barrel in azimuth, v sε is the velocity of the gun barrel in the elevation direction; in the unstable reference system OX pg Y pg Z pg In the figure, the length of the gun barrel is d, and the azimuth velocity of the gun barrel is assumed to be w. β , the pitch angular velocity is w ε , then the velocity converted to the muzzle is: in sβ =in β dcosβ v sε =w ε d Define v sβx ,v sβy They are v sβ In the unstable gun reference system X pg ,Y pg ,Z pg The projection component of , then we can get: Define v sεx ,v sεy ,v sεz They are v ε In the unstable gun reference frame, X pg ,Y pg ,Z pg Axis projection component, we can get: Define v sx ,v sy ,v sz are the velocity v caused by the gun's follow-up motion at the muzzle s In the unstable gun reference system X pg ,Y pg ,Z pg The projection components of the three axes, the velocity caused by the gun's follow-up motion at the muzzle is the result of the superposition of the barrel's vectors in azimuth and elevation: Step 6: Since the three reference axes of the unstable gun reference system and the unstable ship reference system are in the same direction, but the reference origin is different, the involved velocity vector v caused by the gun following motion in the unstable gun reference system is s Transform to the unstable ship reference system through translation; Define v h is the effect of the composite disturbance on the initial velocity of the projectile at the muzzle, then the effect of the composite disturbance on the initial velocity of the projectile at the muzzle is: v h =v c +v s +v yb 。 4. The method for fine correction of various parameters of naval gun firing under composite disturbance according to claim 3 is characterized in that: Step 3, unify the coordinate system, and correct the initial velocity of the projectile by vector superposition method. The corrected initial velocity of the projectile is the sum of the ship's navigation speed, the velocity involved in the follow-up motion of the ship's gun, and the additional velocity vector generated by the ship's swaying motion; introduce the corrected initial velocity of the projectile into the hit equation group, use the iterative method to solve the corrected shooting parameters, and adjust the firing angle of the ship's gun according to the ship's posture, as follows: Define the corrected initial velocity of the projectile under the composite disturbance as v he , then the corrected initial velocity of the projectile in the unstable ship reference system is: v he =v0+v h Define the corrected initial velocity of the projectile in the ship's geographic reference system as v d According to the coordinate transformation principle, the corrected initial velocity of the projectile is transformed from the unstable reference system of the ship to the geographic reference system of the ship, and the corrected initial velocity of the projectile under the geographic reference of the ship is obtained as follows: Define v dx ,v dy ,v dz is the corrected initial velocity of the projectile v d In the ship's geographic reference system OX w Y w Z w The projected velocity component of the projectile, then the equations for the hit variables after the initial velocity correction of the projectile under the composite disturbance are: Define Δβ(t), Δε(t), and ΔT(t) as the correction values ​​of the various parameters of the naval gun firing under the composite disturbance; under the composite disturbance, the naval gun firing azimuth before the initial velocity correction of the projectile is β r , the pitch angle is ε r , the flight time is T r ; The corrected naval gun firing azimuth is β d , the pitch angle is ε d , the flight time is T d ; Then the correction of the various elements of naval gun firing is:

5. A computer device comprising a memory, a processor and a computer program in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method according to any one of claims 1 to 4 are implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method described in any one of claims 1 to 4 are implemented.

7. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method described in any one of claims 1 to 4 are implemented.

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