A simulation algorithm for fire damage assessment of direct naval gun fire on land

Abstract

The present invention belongs to the technical field of fire damage assessment of naval guns firing on land, and specifically relates to a fire damage assessment simulation algorithm for direct naval gun firing on land. Based on the distribution density and a certain damage probability, the present invention proposes an optimal fire distribution scheme for direct naval gun firing. By calculating the mathematical analysis and probability distribution model of the impact point and the coverage area, the relationship between the hit probability and the visible area, the relationship between the hit probability and the shooting distance, etc., the damage effect of direct firing can be effectively calculated.

Description

Technical Field

[0001] The invention belongs to the technical field of fire damage assessment for ship-to-land firing by ship guns, and in particular relates to a fire damage assessment simulation algorithm for direct firing by ship guns on land. Background Art

[0002] In view of the problem that the damage effectiveness of direct fire from naval guns to land is mostly calculated by approximate analytical calculation, a method based on shooting process simulation is proposed, and the application of the simulation method of direct fire process of naval guns in the calculation of damage effectiveness is discussed, providing commanders with important reference data such as the probability of damage to a single target of naval guns on land and the mathematical expectation of the percentage of damage to cluster targets. The design kill rate-target value algorithm is applied to the direct fire ground consumption model. The algorithm is used to determine the system-to-system results of each shooting type-target type pair within the time period set by the user. This method has a small amount of calculation and a fast calculation speed. The algorithm can predict the damage degree of direct fire from naval guns to land, and provides an effective simulation calculation method for commanders to make combat decisions of naval guns to attack land.

[0003] Fire damage: Fire damage refers to the degree of damage that can be achieved when striking a target. It reflects the weapon system's ability to damage the target and is one of the important indicators for examining the performance of the weapon system and the completion of combat missions.

[0004] Direct fire: It is the shooting conducted by aiming the weapon directly at the target; it is an important means to destroy enemy point-shaped solid targets and armored targets. The killing effect of direct fire is mainly determined by factors such as weapon type, type of ammunition used, shooting distance, target status (area, moving or stationary, heading, etc.), hit probability, and damage probability (on average, an odd number of hits must be made).

[0005] Damage range: Target damage range refers to the range with the center of the target as the center point. If the projectile falls within this range, the target will definitely be damaged; if it falls outside this range, the target will definitely not be damaged. Ammunition damage range refers to the area covered by the damage radius with the projectile landing point as the center point. The target within this area will definitely be damaged, otherwise the target will definitely not be damaged. The degree of damage to the target depends on the relative position of the projectile landing point and the target. Usually, the target damage range and the ammunition damage range are not distinguished, and are collectively referred to as the damage range. The target damage range is used when solving the target damage probability, and the ammunition damage range is often used when calculating the damage area. Summary of the invention

[0006] The shooting process calculation of the present invention simulates the impact point position according to the shooting error composition and the aiming point position, judges whether the impact point falls within the target damage range by comparing the relative positions of the impact point and the aiming point, counts the number of impact points falling within the target damage range, and calculates the shooting fire damage assessment according to the damage probability.

[0007] The technical solution of the present invention is as follows:

[0008] Applying the direct fire target attrition model applies the kill rate-target assessment algorithm to determine the calculations for each fire type-target type.

[0009] The algorithm is used to calculate the direct fire effect of naval guns on land targets. Naval guns are assigned to fire concentration points. The algorithm establishes the shooter's fire concentration point and target list, assigns targets to naval guns based on the firing range and weapon direction of the weapon type, and assigns targets to naval guns based on the number of targets and kill rate of the weapon type.

[0010] Basic algorithm process:

[0011] (1) Data preparation, including two types: shooting parameters and target parameters.

[0012] Shooting parameters include weapon type, ammunition type, shooting unit, shooting distance, and shooting time interval.

[0013] ① Weapon type: different weapon types have different shooting effects; this algorithm is mainly used for naval guns, but is also applicable to other types of cannons, etc.

[0014] ②Ammunition type. In order to achieve the greatest shooting effect, different types of ammunition should be used for different types of targets, such as armor-piercing shells, armor-piercing shells, grenades, extended-range shells, etc.

[0015] ③Firing unit: generally, shooting is carried out by the ship itself.

[0016] ④ Shooting distance has a significant impact on the hit rate of direct shooting, and the hit probability decreases significantly with the increase of shooting distance;

[0017] ⑤ Shooting time interval, the time interval between continuous firing when naval guns shoot at targets.

[0018] The target parameters mainly include:

[0019] ① The visible height H of the target, the visible width W of the target, and the average number of bullets required to destroy the target.

[0020] ② Target state parameters, moving or stationary and path angle (or deflection angle).

[0021] ③ The number of bullets required to damage the target can be obtained by looking up the table based on the type of target and the type of our weapons and ammunition: using n type i bullets can destroy a type j target, where n is the number of ammunition required to destroy the modified target.

[0022] (2) Calculate the hit probability.

[0023] ① Calculation of hit probability. The parameters to be used include the height and direction error of the shot. Different weapons and different types of ammunition have different shooting errors when shooting at targets, which need to be obtained through special data.

[0024] The main factors affecting the hit rate are height probability deviation, direction probability deviation, visible height and visible width of the target.

[0025] (3) Damage calculation, including damage probability calculation and ammunition consumption calculation.

[0026] ① When N direct-fire weapons are firing at M targets, especially at multiple armored moving targets, multiple damage probability values ​​need to be calculated. That is, the probability of damage when the i-th weapon shoots the j-th target i=1,…,N; j=1,…M can generally be expressed as an average value The value represents all use.

[0027] ② Considering the impact of battlefield environmental factors, the probability of hit and the probability of damage under normal battlefield environmental conditions decrease by an average of 20% to 30%. Therefore, it is necessary to modify the calculated damage probability. The coefficient range of the value is 0.7~0.8.

[0028] ③ Calculation of the minimum amount of ammunition to destroy the target: the minimum amount of ammunition required to attack a certain type of target is calculated through data such as the probability of damage.

[0029] A simulation algorithm for fire damage assessment of direct fire from naval guns to land, the steps are as follows:

[0030] Step 1: Calculate the hit probability

[0031] In the case of discrete shooting, when shooting at a target, assuming that the probability of hitting the target with the i-th shot is p i , then the probability of missing the target is q i =1-p i , each shot is an independent event. Let X be the number of shots used to hit the target for the first time, which is a discrete random variable. The probability of hitting the target after n shots is:

[0032]

[0033] According to the probability in the above formula, the average number of shots required to shoot and hit is:

[0034]

[0035] When the probability of hitting the target in the i-th shot is a constant, that is, p i =p, i=1,2,…, then

[0036]

[0037] The key factors affecting the hit probability include the target's visible width W, the target's visible height H and the shooting distance L.

[0038] Since the target shape is usually irregular, the methods used to calculate the visible area of ​​the target include area ratio and grid method. The grid method divides the target into several grids, and obtains the hit probability of each grid by integrating each grid. Finally, the overall hit probability is obtained. The hit probability expression is as follows:

[0039] P = ∫∫∫f(x,y,z)dv

[0040] f(x,y,z) is the expression of the relationship between the target visible area and distance

[0041]

[0042] Where α f is the target front angle; α g is the side angle; P f is the hit probability without considering the visible area; W is the visible width of the target; L is the visible length of the target; a is the incident angle.

[0043] Step 2: Calculate the probability of damage / kill rate

[0044] According to the coverage of our weapon damage area and target area (without considering the hit probability), the area damage probability can be obtained, which is described by the following formula:

[0045] Assume that our forces’ firepower range is larger than the target area, and δ x ≥l x ,

[0046] δ z ≥l z , then E(x) is as follows

[0047]

[0048] Where x is the distance between the explosion point and the target center in the x direction; z is the distance between the explosion point and the target center in the z direction; l x is the target depth / 2; l z is the target front / 2; δ x is the power depth / 2; δ z is Power Positive / 2;

[0049] |x|<δ x -l x The target area is completely covered by our fire damage area;

[0050] δ x -l x ≤|x|≤δ x +l x The area damaged by our firepower partially intersects with the target area;

[0051] The probability of damaging the target is:

[0052] P(x)=p i ·E(x)

[0053] In the formula, p i is the probability of hitting the target; E(x) is the probability of damaging the target area.

[0054] Step 3: Calculate Shooting Error

[0055] Shooting error: refers to the deviation of the explosion point from the aiming point at any launch point during shooting;

[0056] Error: includes element errors, dispersion errors and shooting errors;

[0057] Errors of various elements: The deviation of the center point of the scatter from the aiming point is called the error of various elements;

[0058] is the error in distance, is the error in the shooting direction. The error obeys a two-dimensional normal distribution. The distribution density expression is as follows:

[0059]

[0060] Where: x, z are the coordinates of the scatter center;

[0061] ρ is the normal constant, and its value is 0.476936;

[0062] E d ,E f is the intermediate error of distance and direction of the elements;

[0063] Dispersion error: The deviation of the explosion point from the dispersion center is the dispersion error;

[0064] The distribution density of the scattered error is:

[0065]

[0066] Where: x′, z′ are the coordinates of the explosion point;

[0067] B d B f It is the median error of the scattered distance and direction, that is, the half-value of the scattered (distance, direction) error;

[0068] Shooting error: It is the sum of the deviations of the center of dispersion from the aiming point and the explosion point from the center of dispersion;

[0069] According to the vector operation rules, the shooting error is described by the following formula:

[0070]

[0071] Where: E x Indicates the distance error of the shooting;

[0072] E z Indicates the directional error of the shooting;

[0073] Step 4: Calculate Corrected Kill Ratio

[0074] Based on the time required to acquire the target, the modified kill rate is described by the following formula:

[0075]

[0076] Where: mKR ij The corrected kill rate is: the rate at which shooters of type i are able to acquire and kill targets of type j (targets per minute). It is called the corrected kill rate because it is derived from the kill rate and the acquisition rate.

[0077] P ij is the kill rate that a shooter of type i can acquire and kill a target of type j;

[0078] ΔT is the total time required to acquire a target (seconds / each target), and the time is a function of the terrain and environment;

[0079] This is the correction factor for the influence of battlefield environmental factors, usually 0.7 to 0.8.

[0080] Due to the objective existence of shooting errors, the corrected kill rate needs to be calculated based on the shooting errors, which can be described by the following formula:

[0081] P ij =(1.0-(E x ·E z ))

[0082]

[0083] Step 5: Calculate target loss value

[0084] The target loss value is calculated using the following formula:

[0085] The target loss value of firepower concentration point i to firepower concentration point j: that is, the product of kill rate and time, is affected by the line of sight, the ratio of shooters, and the distribution rate of firepower concentration point i to firepower concentration point j.

[0086]

[0087] Where: m is the number of targets (such as manpower or firing points);

[0088] N j is the real number of the target resource item j;

[0089] ω is the number of bullets that must hit the target to damage it, which can be obtained by looking up the table based on the type of target and the type of our weapons and ammunition: using n type i bullets can destroy type j target, and n is the number of ammunition that must hit to destroy the modified target.

[0090] mxD ij To correct the kill rate.

[0091] Beneficial effects of the present invention:

[0092] The present invention proposes an optimal firepower distribution scheme for direct shooting of naval guns based on the distribution density under a certain damage probability. By calculating the mathematical analysis and probability distribution model of the impact point and the coverage area, the relationship between the hit probability and the visible area, the relationship between the hit probability and the shooting distance, etc., the damage effect of direct shooting can be effectively calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 It is a schematic diagram of a directional impact weapon;

[0094] Figure 2 It is a standard band diagram;

[0095] Figure 3 is a schematic diagram of the target visible area;

[0096] Figure 4 is a schematic diagram of the coverage target;

[0097] Figure 5 is a schematic diagram of the errors of various elements;

[0098] Figure 6 It is a schematic diagram of the relationship between hit probability and visible area;

[0099] Figure 7 It is a schematic diagram of the relationship between hit probability and shooting distance;

[0100] Figure 8 It is a schematic diagram of the relationship between shooting error and the deviation of the explosion point from the aiming point. DETAILED DESCRIPTION

[0101] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0102] It should be noted that in the following specific embodiments, when describing the embodiments of the present invention in detail, in order to clearly represent the structure of the present invention for the convenience of explanation, the structures in the accompanying drawings are not drawn according to general proportions, and are partially enlarged, deformed and simplified. Therefore, it should be avoided to understand this as a limitation of the present invention.

[0103] A specific example of the present invention is described in detail below in conjunction with the technical scheme and the accompanying drawings.

[0104] Suppose the list of shooting distances of our weapons of various types of bullets is (unit: meter): 500, 1000, 1500, 2000, 2500, 3000, 4000, 5000, the time interval is 15 minutes, and the main killing weapon is a naval gun of a certain caliber;

[0105] Assume the target is a certain type of tank. According to the equivalent calculation, the number of bullets required to damage the tank with a certain caliber naval gun is 3.

[0106] Assume that the enemy uses a company as a standard combat unit, and the firepower configuration includes 9 main battle tanks:

[0107] The simulation program was compiled using Matlab language, and related calculations were performed.

[0108] The preferred calculation of the relationship between hit probability and visible area is as follows Figure 6 As shown; Secondly, the relationship between the hit probability and the shooting distance is calculated as follows Figure 7 shown.

[0109] According to the data calculation between the hit probability, the visible area and the shooting distance, the data obtained are shown in the following table:

[0110] Table 1 Relationship between hit probability, visible area and shooting distance

[0111]

[0112] The relationship between shooting error and the deviation of the explosion point from the aiming point is as follows: Figure 8 As shown in the figure, based on the shooting error and the number of enemy troops, the naval gun uses a certain type of ammunition for direct shooting, and the calculation result of firepower consumption is obtained:

[0113] Table 2 Consumption calculation results

[0114]

Claims

1. A simulation algorithm for fire damage assessment of direct naval gun fire on land, characterized in that: Here are the steps: Step 1: Calculate the hit probability In the case of discrete shooting, when shooting at a target, assuming that the probability of hitting the target with the i-th shot is p i , then the probability of missing the target is q i =1-p i , each shot is an independent event. Let X be the number of shots used to hit the target for the first time, which is a discrete random variable. The probability of hitting the target after n shots is: According to the probability in the above formula, the average number of shots required to shoot and hit is: When the probability of hitting the target in the i-th shot is a constant, that is, p i =p, i=1,2,…, then The key factors affecting the hit probability include the target's visible width W, the target's visible height H and the shooting distance L; Since the target shape is usually irregular, the methods used to calculate the visible area of ​​the target include area ratio and grid method. The grid method divides the target into several grids, and obtains the hit probability of each grid by integrating each grid. Finally, the overall hit probability is obtained. The hit probability expression is as follows: P = ∫∫∫f(x,y,z)dv f(x,y,z) is the expression of the relationship between the target visible area and distance Where α f is the target front angle; α g is the side angle; P f is the hit probability without considering the visible area; W is the visible width of the target; L is the visible length of the target; a is the incident angle; Step 2: Calculate the probability of damage / kill rate According to the coverage of our weapon damage area and target area (without considering the hit probability), the area damage probability can be obtained, which is described by the following formula: Assume that our forces’ firepower range is larger than the target area, and δ x ≥l x , δ z ≥l z , then E(x) is as follows Where x is the distance between the explosion point and the target center in the x direction; z is the distance between the explosion point and the target center in the z direction; l x is the target depth / 2; l z is the target front / 2; δ x is the power depth / 2; δ z is Power Positive / 2; |x|<δ x -l x The target area is completely covered by our fire damage area; δ x -l x ≤|x|≤δ x +l x The area damaged by our firepower partially intersects with the target area; The probability of damaging the target is: P(x)=p i ·E(x) In the formula, p i is the probability of hitting the target; E(x) is the probability of damaging the target area; Step 3: Calculate Shooting Error Shooting error refers to the deviation of the explosion point from the aiming point at any launch point during shooting; The error includes the error of various parameters, dispersion error and shooting error; Errors of various elements: The deviation of the center point of the scatter from the aiming point is called the error of various elements; is the error in distance, is the error in the shooting direction. The error obeys a two-dimensional normal distribution. The distribution density expression is as follows: Where: x, z are the coordinates of the scatter center; ρ is the normal constant; E d ,E f is the intermediate error of distance and direction of the elements; Dispersion error: The deviation of the explosion point from the dispersion center is the dispersion error; The distribution density of the scattered error is: Where: x ′ ,z ′ is the coordinates of the explosion point; B d B f It is the median error of the scattered distance and direction, that is, the half-value of the scattered (distance, direction) error; Shooting error: It is the sum of the deviations of the center of dispersion from the aiming point and the explosion point from the center of dispersion; According to the vector operation rules, the shooting error is described by the following formula: Where: E x Indicates the distance error of the shooting; E z Indicates the directional error of the shooting; Step 4: Calculate Corrected Kill Ratio Based on the time required to acquire the target, the modified kill rate is described by the following formula: Where: mKR ij The corrected kill rate is: the rate at which shooters of type i are able to acquire and kill targets of type j (targets per minute). It is called the corrected kill rate because it is derived from the kill rate and the acquisition rate. P ij is the kill rate that a shooter of type i can acquire and kill a target of type j; ΔT is the total time required to acquire a target (seconds / each target), and the time is a function of the terrain and environment; is the correction factor for battlefield environmental factors; Due to the objective existence of shooting errors, the corrected kill rate needs to be calculated based on the shooting errors, which can be described by the following formula: P ij =(1.0-(E x ·AND z )) Step 5: Calculate target loss value The target loss value is calculated using the following formula: The target loss value of firepower concentration point i to firepower concentration point j: that is, the product of the killing rate and time, which is affected by the line of sight, the ratio of shooters, and the distribution rate of firepower concentration point i to firepower concentration point j; Where: m is the number of targets; N j is the real number of the target resource item j; ω is the number of bullets that must hit the target to damage it. It can be obtained by looking up the table based on the type of target and the type of our weapons and ammunition: using n bullets of type i to destroy a type j target, n is the number of ammunition that must hit to destroy the modified target; mKR ij To correct the kill rate.

2. The fire damage assessment simulation algorithm for direct naval gun fire on land as claimed in claim 1, characterized in that: The The correction coefficient for battlefield environmental factors is 0.7 to 0.

8.

3. A fire damage assessment simulation algorithm for direct naval gun fire on land as claimed in claim 1 or 2, characterized in that: The ρ is a normal constant, and its value is 0.476936.

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