A Method for Cooperative Deployment of Motorized Chaff Screen

Abstract

The present invention belongs to the field of electronic countermeasure technology, and particularly relates to a method for coordinated deployment of a mobile chaff screen. While maintaining the advantages of traditional chaff screen jamming itself, a chaff screen jamming is configured by coordinating the deployment of chaff projectiles through unmanned aerial vehicles (UAVs) and marine platforms. Based on an improved cuckoo search algorithm, the deployment rate and direction of chaff projectiles are controlled to make the energy centroid of the chaff screen move continuously over time, effectively dealing with the anti-jamming technology of radar seekers and ensuring the successful escape of marine platforms. The advantages of the present invention are as follows: facing the characteristics of airborne threat radar seekers and actual confrontation scenarios, the deployment parameters of chaff projectiles for UAVs and ships are obtained by means of the optimization mechanism of the cuckoo search algorithm. Through the coordination of UAVs and ships, the controllable sequential deployment of multiple chaff projectiles is completed, enabling the centroid of the chaff screen to move continuously over time according to a certain law, accelerating the escape speed of marine platforms, and effectively dealing with anti-jamming technologies such as moving target indication and track-while-scan of radar seekers.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic countermeasures, and particularly relates to a method for collaborative deployment of a mobile chaff screen. Background Art

[0002] To effectively defend against air threat attacks of active radar systems and ensure that marine platforms are not struck, using chaff for targeted passive interference construction is an important method, which has advantages such as low cost, easy use, and the ability to interfere from the main lobe of the radar. However, with the application of radar anti-jamming technologies such as moving target indication in threat targets, the interference effectiveness of traditional chaff deployment methods has been greatly reduced. Therefore, it is necessary to propose a new deployment idea.

[0003] From the publicly available information, some research results on chaff interference implementation have been accumulated. Some of them are based on the collaborative concept, combining chaff deployment with active interference or the maneuverability of the platform itself to explore methods to improve the interference effect; for example, coordinating active suppression interference with chaff interference to enhance the interference ability by directly irradiating the diffusion cluster with the interference beam; obtaining effective platform maneuvering and chaff deployment plans by studying the combination of helicopter maneuvering, marine platform maneuvering and chaff interference; generally speaking, the above research results have effectively avoided the drawbacks of traditional chaff interference to a certain extent, but due to the high requirements for the cooperation of both parties in space and time, their feasibility in complex actual environments remains to be discussed. Another group of scholars proposed the chaff screen interference concept, which forms an effective shield for the equipment by deploying several chaffs at one time in the direction of the incoming air threat; such chaff screen interference methods have strong feasibility, but since the curtain wall is deployed in advance at one time, its centroid remains fixed and cannot effectively avoid anti-jamming technologies such as moving target indication of the radar seeker. Even with later supplementary deployment measures, the deployment platform is the protected target itself. Once the timing is not mastered scientifically enough, it is easy to expose the target and have the opposite effect. Summary of the Invention

[0004] In view of the above technical problems, the purpose of the present invention is to provide a method for collaborative deployment of a mobile chaff screen. While maintaining the advantages of traditional chaff screen interference itself, it constructs chaff screen interference by deploying chaff projectiles through the cooperation of unmanned aerial vehicles and marine platforms, and controls the deployment rate and direction of chaff projectiles based on an improved cuckoo search algorithm, so that the energy centroid of the chaff screen moves continuously over time, effectively dealing with radar seeker anti-jamming technologies and ensuring the successful escape of marine platforms.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A method for coordinated deployment of a motorized chaff screen, in which a marine platform and an unmanned aerial vehicle cooperate to release chaff bombs. Among them, the marine platform releases chaff bombs to conceal its own target to ensure that the air threat radar seeker cannot detect the marine platform. The unmanned aerial vehicle releases chaff bombs in a direction basically opposite to that of the marine platform to gradually increase the distance between the centroid of the chaff screen energy and the marine platform until the marine platform successfully escapes from the tracking range of the air threat radar seeker.

[0007] It includes the following specific steps:

[0008] Step 1: Construct a model of the motion characteristics of the air threat and a model of the motion characteristics of the marine platform. The steps include:

[0009] Step 101: For the model of the motion characteristics of the air threat, it is determined according to the guidance law (tracking method, parallel approach method, proportional navigation method) adopted by the seeker, and the position coordinates of the air threat changing with time are solved.

[0010] Step 102: For the model of the motion characteristics of the marine platform, it is determined by establishing a functional relationship between the position of the marine platform, time, and the coordinate position at the initial moment.

[0011] Step 2: Construct a model of the characteristics of the motorized chaff screen. The steps include:

[0012] Step 201: Construct a model of the shape of the motorized chaff screen, specifically including:

[0013] (1) Calculate the average effective reflection area and the average effective reflection radius after a single chaff bomb is completely dispersed.

[0014] (2) Define the distance between two adjacent chaff bombs, which is less than 2 times the average effective reflection radius R, and then determine the length of the chaff screen at time t.

[0015] Step 202: Construct a model of the motion of the motorized chaff screen. The steps include:

[0016] (1) According to the positions of the marine platform and the air threat, wind direction, wind speed, the distance between two adjacent chaff bombs, and the deflection angle of the chaff screen axis relative to the normal direction of the initial projectile-target direction, obtain the expressions for the directions of the chaff bombs released by the marine platform and the unmanned aerial vehicle respectively, the time difference and the distance between the releases of two adjacent chaff bombs, and the number of chaff bombs released.

[0017] (2) Calculate the initial release position coordinates and the initial release time of each chaff bomb, as well as the position coordinates of each chaff bomb, the centroid coordinates of the formed chaff screen energy, and the coordinates of the edge points at time t.

[0018] Step 203: Construct a chaff replenishment strategy. The steps include:

[0019] (1) When the continuous diffusion time of a certain chaff projectile is greater than the effective action time of the chaff projectile, at least one replenishment ammunition is required; according to the detonation moment of the aerial threat, calculate the number of replenishment ammunition corresponding to each chaff projectile, and the replenishment position is the position of the chaff projectile at the replenishment moment.

[0020] (2) Calculate the total number of chaff replenishment ammunition before the detonation of the aerial threat.

[0021] Step 3: Construct a maneuverable chaff screen interference effectiveness model, and the steps include:

[0022] Step 301: Construct an interference effectiveness objective function by comprehensively considering the distance between the energy centroid of the chaff screen wall and the centroid of the offshore platform, the flight loss of the unmanned aerial vehicle, the consumption of chaff projectiles, and the definition of the number of chaff replenishment ammunition.

[0023] Step 302: Construct interference effectiveness constraint conditions, and the specific steps include:

[0024] (1) Construct a shielding effectiveness condition, which includes two sub-conditions: one is that the included angles formed by the two edge points of the chaff screen with the centroid of the aerial threat and the centroid of the offshore platform are both smaller than the included angles formed by the two edge points with the aerial threat, proving that the offshore platform is within the shielding range of the chaff screen; the other is that the offshore platform and the aerial threat are on both sides of the chaff screen.

[0025] (2) Construct a towing effectiveness condition, which includes two sub-conditions: one is that the included angle formed by the centroid of the offshore platform, the centroid of the aerial threat, and the energy centroid of the chaff screen is greater than the tracking beam angle of the radar seeker; the other is that at the detonation moment, the distance between the centroid of the offshore platform and the energy centroid of the chaff screen is greater than the killing radius of the aerial threat.

[0026] (3) Construct a resource loss constraint condition, which includes two sub-conditions: one is that the amount of chaff projectiles consumed by the unmanned aerial vehicle and the offshore platform respectively is less than the initial loaded amount of chaff projectiles on the platform; the other is that the flight distance of the unmanned aerial vehicle is less than the maximum flyable distance.

[0027] (4) Construct a launch capacity constraint condition, and the distance for the offshore platform to launch each chaff projectile needs to be less than the maximum launchable distance.

[0028] Step 4: Use the cuckoo search algorithm to obtain the best deployment plan. Through parameter initialization, population individual initialization, and optimization iteration process, output the global optimal solution. The optimization parameters include the chaff projectile deployment rates of the offshore platform and the unmanned aerial vehicle, the distance between the position of the first chaff projectile deployed by the offshore platform and the initial position of the offshore platform, the maneuvering angle of the offshore platform, and the deflection angle of the chaff screen axis relative to the normal direction of the initial projectile-target direction. The obtained deployment plan parameters are the initial deployment position and deployment moment of each chaff projectile, the replenishment position and replenishment moment of the replenishment ammunition.

[0029] Compared with the existing technology, the beneficial effects of the present invention are: based on the cuckoo search algorithm, with the help of drones and offshore platforms to coordinate the deployment of chaff bombs, the motorized chaff curtain is constructed to form a chaff curtain interference with the active radar seeker of air threats, in which the energy center of mass of the chaff curtain moves continuously over time, effectively responding to the new anti-interference technology of radar seekers. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall process of the motorized chaff curtain coordinated deployment method of the present invention;

[0031] Figure 2 is an iterative optimization curve graph obtained in an embodiment of the present invention;

[0032] Figure 3 It is a schematic diagram of a motorized chaff curtain deployment scheme obtained in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following uses the case of an air threat attacking a sea platform target based on the proportional guidance method, and the sea platform and the UAV cooperating to conduct a motorized chaff curtain interference construction to specifically illustrate the implementation process of the present invention. Figure 1 As shown, the specific steps include:

[0034] Step 1: Construct a model of the air threat and maritime platform motion characteristics. The steps include:

[0035] Step 101: Calculate the position coordinates of the air threat based on the proportional guidance mechanism (Equation (1)).

[0036]

[0037] In formula (1), [M x (t),M y (t)] represents the position coordinates of the air threat M at time t, v m Indicates the air threat attack rate, B m (t) represents the angle between the attack direction of the air threat and the baseline at time t, and Δt represents the time difference between time t-1 and time t.

[0038] Step 102: Calculate the position coordinates of the offshore platform, as shown in formula (2):

[0039]

[0040] In formula (2), [S x (t),S y (t)]、[S x (0),S y (0)] represent the coordinate positions of the offshore platform S at time t and the initial time, ω sLet α represent the maneuvering angle of the offshore platform, β represent the initial maneuvering angle of the offshore platform, and Δβ represent the maneuvering rotation angle of the offshore platform.

[0041] Step 2: Construct a characteristic model of a motorized chaff screen. The steps include:

[0042] Step 201: Construct a morphological model of a single-shot chaff projectile:

[0043] (1) Calculate the average effective reflection area and the average effective reflection radius after a single-shot chaff projectile is fully dispersed. Considering the mutual coupling effect and the chaff damage factor comprehensively, the obtained results are shown in Equations (3) and (4):

[0044]

[0045]

[0046] In Equations (3) and (4), σ N represents the average effective reflection area after a single-shot chaff projectile is fully dispersed, N represents the number of chaff strands of a single-shot chaff projectile, λ represents the wavelength of the radar electromagnetic wave, represents the average effective reflection area of a half-wavelength chaff strand, and its size is 0.17λ 2 , and R represents the average effective reflection radius after a single-shot chaff projectile is fully dispersed.

[0047] (2) Define the distance between two adjacent chaff projectiles as Then the length L C (t) of the chaff screen at time t is shown in Equation (5):

[0048]

[0049] In Equation (5), n(t) represents the total number of chaff projectiles released at time t, represents the preset distance between adjacent chaff projectiles to be released.

[0050] Step 202: Construct a motion model of the chaff screen:

[0051] (1) According to the positions of the offshore platform and the aerial threat, the wind direction, the wind speed, the distance between two adjacent chaff projectiles, and the deflection angle of the chaff screen, obtain the expressions for the time difference (Equation (6)), the distance between two adjacent chaff projectiles (Equation (7)), the release direction of the chaff projectiles (Equation (8)), and the number of chaff projectiles released (Equation (9)) between the offshore platform and the UAV for releasing two adjacent chaff projectiles;

[0052]

[0053] L i = v i Δt i (i = 1, 2) (7)

[0054]

[0055]

[0056] In formulas (6) to (9), when i is 1 and 2, they respectively represent the offshore platform and the UAV platform; in formula (6), Δt i represents the time difference between the deployment of two adjacent chaff rockets by platform i, and v i represents the deployment rate of chaff rockets by platform i, and v W represents the wind speed, and ω W represents the wind direction, which is different in different confrontation scenarios. When M y (0) > 0 and S x (0) > 0, when M y (0) > 0 and S x (0) < 0, when M y (0) < 0 and S x (0) < 0, when M y (0) < 0 and S x (0) > 0, γ represents the angle between the missile-target direction and the Y-axis at the initial moment, and the acquisition method is as shown in formula (10); α is the deflection angle of the chaff screen axis direction relative to the normal of the initial missile-target axis; in formula (7), L i represents the interval between the deployment of two adjacent chaff rockets by platform i; in formula (8), represents the deployment direction of chaff rockets by platform i, specifically the angle between the deployment direction and the normal direction of the chaff screen axis; in formula (9), n(t) is the total number of chaff rockets deployed, and n i (t) and n2(t) respectively represent the number of chaff rockets deployed by platform i at time t.

[0057]

[0058] (2) Calculate the initial deployment position coordinates and initial deployment time of each chaff rocket, as well as the position coordinates of each chaff rocket, the energy centroid coordinates and edge point coordinates of the formed chaff screen at time t; s

[0059] ① Initial deployment position of chaff rocket

[0060] represents the initial deployment position coordinates of the j-th chaff rocket C ij launched by platform i, specifically as shown in (i) to (ii).

[0061] (i) C 11 and C 21Initial deployment position

[0062]

[0063] In Equation (11), the magnitudes of k1, k2, k3, and k4 are different in different confrontation scenarios. When M y (0) > 0 and S x (0) > 0, k1 = 1, k2 = 2; when k3 = 2, k4 = 2; when k3 = 1, k4 = 1; when M y (0) > 0 and S x (0) < 0, k1 = 2, k2 = 2; when k3 = 2, k4 = 1; when k3 = 1, k4 = 2. When M y (0) < 0 and S x (0) < 0, k1 = 2, k2 = 1; when k3 = 2, k4 = 2; when k3 = 1, k4 = 1; when M y (0) < 0 and S x (0) > 0, k1 = 1, k2 = 1; when k3 = 2, k4 = 1; when k3 = 1, k4 = 2; when M y (0)S x (0) > 0, ψ = γ + α, when M y (0)S x (0) < 0, ψ = -γ + α.

[0064] (ii) Initial deployment positions of other chaff projectiles

[0065]

[0066] In Equation (12), k5 to k 10 are different in different confrontation scenarios, and the specific values are shown in Table 1. In Table 1, ω W represents different angular ranges of the wind direction, Ⅰ represents Ⅱ represents Ⅲ represents Ⅳ represents

[0067] Table 1 k5 to k 10 Assignment

[0068]

[0069] ② Real-time position coordinates of chaff projectiles

[0070]

[0071] ③ Centroid coordinates of chaff screen

[0072] In Equation (14), represents the centroid coordinates of the chaff screen at time t.

[0073]

[0074] ④ Coordinates of the edge points of the chaff screen

[0075] In Equation (15), represents the coordinates of the edge points of the curtain wall in the i - direction of the platform at time t. The edge point in the direction of the offshore platform is defined as A, and the edge point in the direction of the UAV is defined as B.

[0076]

[0077] Step 203: Construct a chaff replenishment strategy

[0078] Let the action time after each chaff projectile forms an effective chaff cloud be t e , if t b - t ij > t e , then the chaff projectile C ij needs to be replenished. Considering the chaff projectile release time and the time required to form an effective chaff cloud, it is set that each replenishment needs to be carried out at Δt time before the corresponding chaff cloud fails. Thus, the replenishment times, the time and position of each replenishment are further calculated, as shown in Equations (16) - (20). Among them, g ij represents the number of replenishments required for the chaff projectile C ij , g isum represents the total number of chaff replenishments released by the platform U i , and respectively represent the q3 - th replenishment time and replenishment position of the chaff projectile C ij .

[0079] g ij = floor[(t b - t e - t ij ) / (t e - Δt)] (16)

[0080]

[0081]

[0082]

[0083]

[0084] Step 3: Construct the interference effectiveness model of the motorized chaff screen. The steps include:

[0085] Step 301: Construct the objective function of interference effectiveness, which is defined by comprehensively considering the distance between the energy centroid of the chaff screen and the centroid of the offshore platform, the flight loss of the UAV, the consumption of chaff projectiles, and the number of times of chaff replenishment.

[0086] Equation (21) is the formula for obtaining the objective function of the motorized chaff screen deployment. f represents the value of the objective function; f L represents the distance characterization function between the energy centroid C of the chaff screen and the centroid S of the offshore platform, represents the vector formed by the edge point A of the chaff screen and its energy centroid C at time t, represents the vector formed by the energy centroid C of the chaff screen and the offshore platform S at time t; f h represents the flight loss of the UAV, v2t represents the flight distance of the UAV during the deployment of chaff projectiles, l max represents the maximum flight distance that the UAV can fly; f SC represents the loss of chaff projectiles on the offshore platform side, n 1sum and n 1max respectively represent the release amount of chaff projectiles on the offshore platform and the number of chaff projectiles it is equipped with; f AC represents the loss of chaff projectiles on the UAV side, n 2sum and n 2max represent the deployment amount of chaff projectiles on the UAV and the number of chaff projectiles it is equipped with; λ1, λ2, λ3, and λ4 respectively represent the weight coefficients of f L , f A , f SC and f AC , and there is λ1 + λ2 + λ3 + λ4 = 1; g sum represents the total number of times of chaff replenishment during the confrontation process.

[0087]

[0088] Step 302: Construct the constraint conditions of interference effectiveness.

[0089] (1) Shielding effectiveness constraint condition

[0090] During the entire interference process, when the air threat and the offshore platform are always on both sides of the chaff screen, and the offshore platform is always effectively shielded by the chaff screen and cannot be detected by the air threat, it is determined that the shielding is effective, as shown in Equations (22) and (23). In Equation (22), represents the axis equation of the chaff screen at time t. Substitute the centroid coordinates of the air threat [M x (t), M y (t)] and the centroid coordinates of the offshore platform Substituting into the equation, when the product z1 of the two function values obtained is less than 0, it indicates that the air threat and the maritime platform are on both sides of the axis of the chaff curtain wall; in Equation (23), ∠AMS and ∠BMS represent the angles formed by the two edge points A and B of the chaff curtain at time t with the centroid M of the air threat and the centroid S of the maritime platform respectively, and ∠AMB represents the angle formed by A, M, and B. When both ∠AMS and ∠BMS are less than ∠AMB, that is and are both less than 0, z2 is -1, which proves that the maritime platform is within the shielding range of the chaff curtain wall at this time.

[0091]

[0092]

[0093] (2) Towing effectiveness constraint conditions

[0094] Towing effectiveness means that at the detonation moment of the air threat, the maritime platform successfully escapes from the tracking beam of the air threat radar seeker and the killing range of the air threat, as specifically shown in Equations (24) - (25). Among them, θ M represents the angle of the radar seeker tracking beam, represents the vector formed by point M to the edge point B of the chaff curtain at the detonation time t b of the air threat, represents the vector formed by point M to S at the detonation time t b of the air threat, and θ M represents the angle of the radar seeker tracking beam.

[0095]

[0096]

[0097] (3) Resource consumption constraint conditions

[0098] This constraint condition includes the chaff projectile consumption constraint condition and the UAV flight constraint condition, as specifically shown in Equations (26) - (27). Among them, Equation (26) means that the chaff projectile launch amounts of both the maritime platform and the UAV need to be less than or equal to their own chaff projectile reserves, that is and z5 = -1; Equation (27) means that the UAV flight distance v2t needs to be less than its maximum flight distance l max , that is z6 ≤ 0.

[0099]

[0100] z6 = v2t - l max ≤ 0 (27)

[0101] (4) Launch capacity constraint conditions

[0102] This constraint condition indicates that the distance of each chaff projectile launched from the offshore platform needs to be less than the maximum launch distance, as shown in Equation (28). Among them, z7 is the parameter characterizing this constraint condition, and L 1j represents the distance of the j-th chaff projectile launched from the offshore platform, and L cmax represents the maximum launch distance, represents the difference between the launch distance of the j-th chaff projectile in the direction of the offshore platform and the maximum launch distance. When j = 1, 2, ……, n 1sum When are all less than 0, then z7 is assigned -1, and at this time, the launch capacity constraint condition is satisfied.

[0103]

[0104] Step 4: Use the cuckoo search algorithm to obtain the optimal deployment plan. Through parameter initialization, population individual initialization, and optimization iteration process, the global optimal solution is output; the optimization parameters include the chaff projectile deployment rates of the offshore platform and the UAV, the distance between the position of the first chaff projectile deployed by the offshore platform and the initial position of the offshore platform, the maneuvering angle of the offshore platform, and the deflection angle of the chaff screen. The obtained deployment plan parameters are the initial deployment position and deployment time of each chaff projectile, the position and time of the replacement projectile.

[0105] Step 5: Application scenario description

[0106] The reconnaissance and early warning system discovers an active radar-guided air threat attacking the offshore platform, and immediately conducts self-defense maneuvering chaff screen deployment. Given: At the initial moment, the position coordinates of the air threat and the offshore platform are [0, 10 km] and [15 km, 0] respectively; the flight speed of the air threat is 150 m / s, the initial line-of-sight angle is 0°, the initial air threat speed vector angle is 0°, the maximum kill radius is 100 m, the working frequency of the radar seeker is 3 GHz, and the angular resolution is 0.1 rad; the maximum traveling speed of the offshore platform is 20 knots (10 m / s), the initial traveling direction is 20°, and the maximum chaff projectile launch distance of the offshore platform is 2 km; the maximum flight speed of the UAV is 50 m / s, and the maximum flight distance at one time is 10 km; the total number of chaff projectiles loaded on the UAV and the offshore platform is 30 each, the number of chaffs per chaff projectile is 5×10 6 roots, the distance L1 between adjacent two chaff projectiles is 1.8R, the maximum sustainable time of the single chaff projectile cloud is 60 s, and each replenishment of projectiles needs to be carried out 3 s in advance; the sea breeze is level 4 (7 m / s), and the wind direction is 330°; λ1, λ2, λ3, and λ4 are 0.3, 0.3, 0.2, and 0.2 respectively.

[0107] The iteration optimization curve is as Figure 2As shown, where the abscissa is the number of iterations and the ordinate is the objective function value; the optimization scheme is as Figure 3 shown and is specifically described as follows:

[0108] A total of 6 chaff projectiles are required to configure the motorized chaff screen. No replenishment of projectiles is required during the whole process. When the confrontation process lasts for 50.13 s, the ship sails out of the air threat tracking beam range. At the initial moment, the axial deflection angle of the chaff screen relative to the missile-target normal line is -5.31°, and the ship's maneuvering deflection angle is 29.43°. At the initial moment, 2 and 4 chaff projectiles are respectively deployed by the ship and the UAV, and the deployment directions φ1 and are 29.64° and 75.66° respectively.

[0109] The positions of the 2 chaff projectiles deployed by the ship are (14.75, 0.74) km and (15.12, 0.66) km respectively, and the deployment times are 0 s and 37.85 s respectively.

[0110] The 4 chaff projectiles deployed by the UAV are (14.51, 0.49) km, (14.30, 0.14) km, (14.09, -0.21) km, (13.88, -0.56) km respectively, and the deployment times are 0 s, 15.82 s, 31.64 s, 47.46 s respectively.

Claims

1. A method for collaborative deployment of a motorized chaff screen, characterized in that, The sea platform and the UAV cooperate to release chaff bombs. Among them, the sea platform releases chaff bombs to conceal its own target, so as to ensure that the radar seeker of the air threat cannot detect the sea platform. The UAV releases chaff bombs in the opposite direction to the release direction of the sea platform, so as to gradually increase the distance between the centroid of the chaff screen energy and the sea platform until the sea platform successfully escapes from the tracking range of the radar seeker of the air threat. The specific steps are as follows: Step 1, construct a motion characteristic model of the air threat and a motion characteristic model of the sea platform. The steps include: Step 101, for the motion characteristic model of the air threat, it is determined according to the guidance law adopted by the seeker, and the position coordinates of the air threat changing with time are solved; Step 102, for the motion characteristic model of the sea platform, it is determined by establishing a functional relationship between the position of the sea platform, time and the coordinate position at the initial moment; Step 2, construct a characteristic model of a motorized chaff screen. The steps include: Step 201, construct a morphological model of a motorized chaff screen, specifically including: (1) Calculate the average effective reflection area and the average effective reflection radius after a single chaff bomb is completely dispersed; (2) Define the distance between two adjacent chaff bombs, and this distance is less than 2 times the average effective reflection radius R, and then determine the length of the chaff screen at time t; Step 202, construct a motion model of a motorized chaff screen. The steps include: (1) According to the positions of the sea platform and the air threat, wind direction, wind speed, the distance between two adjacent chaff bombs, and the deflection angle of the chaff screen axis relative to the normal direction of the initial missile-target direction, obtain the expressions of the directions for the sea platform and the UAV to release chaff bombs respectively, the time difference and the release distance between two adjacent chaff bombs, and the number of chaff bombs to be released; (2) Calculate the initial release position coordinates and the initial release time of each chaff bomb, as well as the position coordinates of each chaff bomb at time t, the centroid coordinates of the formed chaff screen energy and the coordinates of the edge points; Step 203, construct a chaff replenishment strategy. The steps include: (1) When the continuous diffusion time of a certain chaff bomb is greater than the effective action time of the chaff bomb, at least one replenishment is required; according to the detonation moment of the air threat, obtain the number of replenishment times corresponding to each chaff bomb, and the replenishment position is the position of the chaff bomb at the replenishment moment; (2) Calculate the total number of chaff replenishments before the air threat detonates; Step 3, construct an interference effectiveness model of a motorized chaff screen. The steps include: Step 301, construct an interference effectiveness objective function by comprehensively considering the distance between the centroid of the chaff screen wall and the centroid of the sea platform, the flight loss of the UAV, the consumption of chaff bombs, and the definition of the number of chaff replenishments; Step 302, construct interference effectiveness constraint conditions. The specific steps include: (1) Construct a shielding effectiveness condition, which includes two sub-conditions: one is that the angles formed by the two edge points of the chaff screen with the centroid of the air threat and the centroid of the sea platform are both smaller than the angles formed by the two edge points with the air threat, which proves that the sea platform is within the shielding range of the chaff screen; the other is that the sea platform and the air threat are on both sides of the chaff screen; (2)Construct the towing effectiveness conditions, including two sub-conditions: one is that the included angle formed by the centroid of the offshore platform, the centroid of the air threat, and the centroid of the chaff screen energy is greater than the tracking beam angle of the radar seeker; the other is that at the detonation moment, the distance between the centroid of the offshore platform and the centroid of the chaff screen energy is greater than the kill radius of the air threat; (3)Construct the resource consumption constraint conditions, including two sub-conditions: one is that the amount of chaff ammunition consumed by the UAV and the offshore platform respectively is less than the initial loaded chaff ammunition amount of the platform; the other is that the flight distance of the UAV is less than the maximum flyable distance; (4)Construct the launch capacity constraint conditions, and the distance of each chaff ammunition launched by the offshore platform needs to be less than the maximum launchable distance; Step 4, use the cuckoo search algorithm to obtain the optimal deployment plan, and output the global optimal solution through parameter initialization, population individual initialization, and optimization iteration process; the optimization parameters include the chaff ammunition deployment rates of the offshore platform and the UAV, the distance between the position of the first chaff ammunition deployed by the offshore platform and the initial position of the offshore platform, the maneuvering angle of the offshore platform, and the deflection angle of the chaff screen axis relative to the normal of the initial missile-target direction. The obtained deployment plan parameters are the initial deployment position and deployment time of each chaff ammunition, and the position and time of the supplementary ammunition.

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