Cooperative Terminal Strike Method of Loitering Munitions Based on Impact Angle and Time Constraints

Abstract

The present invention relates to a technology based on time coordination and belongs to the field of guidance technology. That is, the terminal guidance algorithm can perform time constraints to solve the problem of terminal cooperative strike. By decoupling the time constraint and the impact angle constraint, time control is realized in the lateral plane. And on this basis, taking the remaining time as the coordination variable, a cooperative terminal guidance strategy using a two-layer architecture is used to achieve the cooperative strike of multiple cruise missiles on the target. Thus, the problems of easily reducing the impact angle and time constraint control capabilities of the guidance algorithm and easily causing mutual interference between impact angle control and time control, which affect the miss distance, impact angle and time control accuracy, are solved.

Description

Technical Field

[0001] The present invention belongs to the field of guidance technology, and particularly relates to a method for cooperative terminal strike of a loitering munition based on impact angle and time constraints. Background Art

[0002] In recent years, the research on loitering munition technology has become a hot topic of key concern. A loitering munition combines the basic characteristics of an unmanned aerial vehicle and a missile, and can cruise in the target area to achieve single or multiple tasks such as situation awareness, communication relay, area control, target indication, electronic interference, precision strike, and damage assessment. Compared with missiles, loitering munitions have high intelligence, long loitering time, and low cost, and are usually used as cluster munitions. The terminal guidance section of a loitering munition should have the ability of time cooperative operation. For a loitering munition with limited warhead power, in order to enhance the strike effect, it is often required that the terminal guidance of the loitering munition can have the ability of cooperative synchronous directional strike.

[0003] The current control methods of loitering munitions still have the following problems:

[0004] Firstly, the research methods of current terminal guidance laws with impact angle constraints all have great limitations. For example, using an adaptive proportional guidance law to guide a hypersonic vehicle, and changing the proportional coefficient to perform vertical strikes on stationary targets. This guidance scheme has limited anti-interference ability and discontinuous guidance commands. When using the prediction-correction method to solve the impact angle constraint problem, this method requires high computing power on the missile. In addition, the above terminal guidance laws with impact angle constraints do not consider the problem of synchronous strike time control.

[0005] Secondly, the research on terminal guidance laws with both impact angle and time constraints is relatively less. The current research methods can better solve the time constraint or directional cooperative strike problem, but they have not well solved the problem that the time control term is prone to zero singularity in the real-time environment on the missile, as well as the problem of the mutual influence between time control and impact angle constraint. Summary of the Invention

[0006] Technical Problems to be Solved

[0007] In order to solve the problem of cooperative strike in the terminal guidance stage of multiple loitering munitions, based on a two-layer cooperative guidance architecture, the present invention proposes a method for cooperative terminal strike of a loitering munition with impact angle and time constraints in three-dimensional space. This method adopts a two-layer architecture to achieve multi-munition cooperation and strike the target at a specified time and direction. By decoupling the angle control and time control, the impact angle and time control are synchronously realized, and the problems of terminal guidance impact angle and time constraints are solved.

[0008] Technical Solution

[0009] A cooperative terminal strike of a loitering munition based on impact angle and time constraints is characterized by the following steps:

[0010] Step 1: Each loitering munition estimates the remaining time t to reach the target using the local guidance law go and the time control term weight coefficient α, and sends them to the cooperative control device of the lead munition in the loitering munition formation;

[0011] The remaining time t go :

[0012] t go =(1 - ω)·t goD +ω·t goL

[0013] where ω ∈ [0, 1] is a weight coefficient,

[0014] t goD is the estimated value of the remaining time in the longitudinal plane, and its expression:

[0015] t goD =t goD,PN +t goD,B

[0016]

[0017]

[0018] where r is the relative distance between the loitering munition and the target, is the desired missile-target distance, is the square of the desired lead angle, μ is the angular deviation weight coefficient, V M is the flight speed, N D is the longitudinal plane guidance coefficient; φ is the line-of-sight elevation angle, θ is the ballistic inclination angle, μ is the angular deviation weight coefficient, ε is the angular deviation;

[0019] t goL is the remaining time of the lateral plane guidance law, and its expression:

[0020]

[0021] where N L is the lateral plane guidance coefficient, s is the projection of the missile-target line in the lateral plane, V MT is the projection of the loitering munition speed on the horizontal plane, is the square of the lead angle in the turning plane;

[0022] Step 2: The cooperative control device calculates the expected remaining time ξ of the loitering munition formation using the distributed weighted average consensus algorithm * ;

[0023]

[0024] Among them, t go,i is the remaining time for the i-th loitering munition to reach the target, and n is the total number of loitering munitions; α i is the time control term weight coefficient of the i-th loitering munition;

[0025] Step 3: The expected remaining time ξ after the leading munition collaborative calculation * is broadcast to all loitering munition members within the swarm formation. After each member receives the unified expected remaining time ξ * , it calculates the guidance control quantity according to the local guidance law. The entire loitering munition formation completes the collaborative task under the control of decentralized guidance control and hits the target simultaneously.

[0026] A further technical solution of the present invention: The local guidance law described in Step 3 includes a longitudinal plane guidance law and a lateral plane guidance law. The expression of the longitudinal plane guidance law is:

[0027] a MD = a PND + a BD

[0028]

[0029] Among them, ε is the angular deviation;

[0030] The expression of the lateral plane guidance law is:

[0031] a ML = a PNL + a BL .

[0032] A computer system, characterized in that it includes: one or more processors, and a computer-readable storage medium for storing one or more programs. Among them, when the one or more programs are executed by the one or more processors, the one or more processors implement the above method.

[0033] A computer-readable storage medium, characterized in that it stores computer-executable instructions, and the instructions are used to implement the above method when executed.

[0034] Beneficial effects

[0035] A method for cooperative terminal strike of loitering munitions with angle-of-fall and time constraints provided by the present invention is based on time cooperation, that is, the terminal guidance algorithm can perform time constraints, so as to solve the problem of terminal cooperative strike. By decoupling the time constraint and the angle-of-fall constraint, time control is realized in the lateral plane. And on this basis, taking the remaining time as the coordination variable, a cooperative terminal guidance strategy using a two-layer architecture is used to achieve the cooperative strike of multiple loitering munitions on the target. Thus, the problems that are likely to reduce the angle-of-fall and time constraint control capabilities of the guidance algorithm and are likely to cause mutual interference between angle-of-fall control and time control, affecting the miss distance, angle-of-fall and time control accuracy are solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings are only for the purpose of illustrating specific embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference signs denote the same components.

[0037] Figure 1 Schematic diagram of the geometric relationship between the designed loitering munition and the target movement of the present invention;

[0038] Figure 2 Schematic diagram of the geometric transformation relationship between the designed loitering munition and the target in the longitudinal plane of the present invention;

[0039] Figure 3 Equation of motion of the designed loitering munition in the lateral plane, schematic diagram of the geometric relationship of the lateral plane motion of the present invention;

[0040] Figure 4 Schematic diagram of a cooperative guidance strategy of "decentralized guidance + centralized coordination" designed by the present invention;

[0041] Figure 5 Schematic diagram of the structure of a cooperative guidance algorithm in the terminal attack section designed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] The present invention provides a method for cooperative terminal strike of loitering munitions with fall angle and time constraints. This method mainly adopts a two-layer cooperative architecture: the upper layer uses the remaining time as the coordination variable to achieve multi-munition time coordination; the lower layer is based on the terminal guidance laws of each loitering munition to achieve the strike on the target at a specified time and attack direction. Aiming at the problems of terminal guidance fall angle and time constraints, by decoupling the angle control and time control, that is, performing angle control in the longitudinal plane and time control in the lateral plane, the fall angle and time control are synchronously achieved. First, using the small deviation method, a bias proportional guidance law considering angle constraints is derived in the longitudinal plane. To improve the accuracy of remaining time estimation, a time estimation method considering both the proportional control term and the angle constraint term is derived. Secondly, in the lateral plane, a time control bias proportional guidance law without the problem of zero-crossing singularity and with time-varying adjustable coefficients is given. Finally, to better coordinate the guidance commands in the longitudinal and lateral planes and ensure that the guidance commands are non-singular and can converge synchronously, a time-to-arrival estimation method considering the remaining time in both planes is given. This method is also applicable to the cooperative strike scenario of traditional armor-piercing missiles and other weapon systems.

[0044] In order to simplify the motion process of the terminal guidance section of the loitering munition, the present invention decomposes it into longitudinal plane motion and lateral plane motion. The loitering munition is regarded as a particle, and it is assumed that the loitering munition is always in an instantaneous equilibrium state. The motion geometric relationship between the loitering munition and the target is as Figure 1 shown.

[0045] Assume that a local coordinate system is established with the target located at the origin of coordinates. (x M , y M , z M ) is the spatial coordinate of the loitering munition. θ and ψ are the ballistic inclination angle and the ballistic deflection angle respectively, φ and Ψ are the line-of-sight elevation angle and the line-of-sight azimuth angle respectively, and V M is the flight speed. According to the relative geometric relationship between the loitering munition and the target, the three-degree-of-freedom kinematic equation of the centroid of the loitering munition relative to the ground coordinate system can be obtained as:

[0046]

[0047] To design the loitering munition to hit the target with the desired attitude and improve the damage effect, it is necessary to design the guidance law a M , so that when the ballistic inclination angle θ of the loitering munition approaches t f (the hit moment), θ approaches θ F (the desired ballistic inclination angle).

[0048] The terminal cooperative strike is based on a time-constrained cooperative guidance algorithm. For the attack time control guidance based on independent guidance, the purpose of designing the guidance law is: to design the guidance law a M , so that tf →t d , where t d is the specified attack time. For convenience of expression, define ξ as the time deviation, then ξ can be expressed as

[0049]

[0050] In the formula, is the expected remaining time; t go is the estimated remaining time.

[0051] Based on this, two control methods are proposed: the impact angle constraint guidance algorithm and the time control and cooperative strike strategy.

[0052] The impact angle constraint guidance algorithm proposed this time uses two partial combinations to form a guidance law form with impact angle constraints. The proportional command term mainly enables the loitering munition to successfully hit the target, with the main purpose of reducing the miss distance. The angle control command term is mainly used to control the velocity direction so that the loitering munition can meet the impact angle constraint requirements when hitting the target. For the longitudinal plane, based on the offset proportional form, the guidance law form can be expressed as the following form:

[0053] a MD = a PND + a BD (3)

[0054] Among them, a PND is the longitudinal plane proportional command term, usually N D is the longitudinal plane guidance coefficient; a BD is the offset term (or called the angle control term) of the longitudinal plane guidance law, providing the angle control command.

[0055] For the lateral plane, based on the offset proportional form, the guidance law form can be expressed as the following form:

[0056] a ML = a PNL + a BL (4)

[0057] Among them, a PNL is the lateral plane proportional command term, usually N L is the lateral plane guidance coefficient; a BL is the offset term (or called the time control term) of the lateral plane guidance law, providing the time control command.

[0058] This collaborative strike strategy is based on time coordination, that is, the terminal guidance algorithm can perform time constraints to solve the problem of terminal collaborative strike. By decoupling the time constraint and the impact angle constraint, time control is achieved in the lateral plane. Based on this, with the remaining time as the coordination variable, a two-layer architecture is used to coordinate the terminal guidance strategy to achieve the collaborative strike of multiple cruise missiles on the target. Thus, the problems of easily reducing the impact angle and time constraint control capabilities of the guidance algorithm and easily causing mutual interference between impact angle control and time control, affecting the miss distance, impact angle, and time control accuracy are solved. The specific collaborative strategy is as follows:

[0059] First, each cruise missile uses the local guidance law (longitudinal and lateral plane guidance laws) to estimate the remaining time t go,i and the weight coefficient α i of the time control term, and sends them to the collaborative control device (coordination layer) of the leading missile in the cruise missile formation;

[0060] Second, the collaborative control device uses the distributed weighted average consensus algorithm to calculate the expected remaining time ξ * of the cruise missile formation;

[0061]

[0062] Third, the leading missile broadcasts the calculated expected remaining time ξ * to all cruise missile members in the swarm formation. After each member receives the unified coordination variable value, it can obtain its guidance control amount according to the local guidance law (calculated using the lateral plane offset ratio). The entire cruise missile formation completes the collaborative task under the control of decentralized guidance control and hits the target simultaneously.

[0063] I. Impact Angle Constraint Guidance Algorithm

[0064] Based on the above design idea, the impact angle constraint guidance algorithm can deduce a formula, and thus draw a conclusion:

[0065] The guidance law form with impact angle constraint consists of two parts: a proportional command term and an angle control term. The proportional command term mainly enables the cruise missile to successfully hit the target, with the main purpose of reducing the miss distance. The angle control command term is mainly used to control the velocity direction so that the cruise missile can meet the impact angle constraint requirements when hitting the target. Therefore, for the longitudinal plane, the guidance law form can be expressed as the following form:

[0066] a MD = a PND + a BD (4)

[0067] Among them, a PND is the proportional command term in the longitudinal plane, usually N Dis the lateral plane guidance coefficient; φ is the line-of-sight elevation angle; a BD is the offset term (or called the angle control term) of the longitudinal plane guidance command, providing the angle control command.

[0068] For the convenience of designing the offset term a B,D , the small deviation design method is adopted. The coordinate system (s, h) is taken as the longitudinal plane inertial coordinate system, and (x R , y R ) is the reference coordinate system; Φ is the angle between the ox R axis and the os axis, with the counterclockwise direction being positive; point M0 is the position corresponding to a state on the aircraft, and point M is the current position of the aircraft. See Figure 2 for details. In the reference coordinate system, θ and φ need to be rewritten as

[0069]

[0070]

[0071] In addition, y is the distance between the current position of the loitering missile and the ox R axis. According to the geometric relationship, and can be expressed as

[0072]

[0073]

[0074] Taking the derivative of Equation (8), another expression form of the longitudinal plane proportional guidance command a PN,D can be obtained as

[0075]

[0076] Considering Combining Equations (4) to (9) and after rearrangement, we can obtain

[0077]

[0078] Given that t goD = t f - t, then solving the above differential equation, we can get

[0079]

[0080] wherein,

[0081]

[0082]

[0083] aPND0 , t goD0 , are respectively a PND , t goD , the initial value at time 0

[0084] Derive Equation (11) and substitute Equation (4) into it. After rearrangement, the expression of θ can be obtained as

[0085]

[0086] Therefore, at time t0, the constraint angle θ F0 can be expressed as

[0087]

[0088] Replace t0 with t, and the constraint angle θ at each moment can be obtained F The value of

[0089]

[0090] Let a BD = 0 in Equation (16), then the part θ of the influence of the proportional navigation command on the constraint angle can be obtained F,PN , which can be expressed as

[0091]

[0092] Combining (16) and (17), and defining ε as the angular deviation, a BD is

[0093]

[0094] In the formula

[0095] ε = (1 - N D )θ F - θ - N D φ (19)

[0096] Since (20) is derived using the small deviation method, to make this angle control command more general, it is corrected to obtain

[0097]

[0098] In the formula, μ is the angular deviation weight coefficient.

[0099] Since it can be obtained

[0100]

[0101] Taking the derivative of ε with respect to time and substituting Equation (22) into it, we get

[0102]

[0103] Given that t go = t f - t, integrating the above equation gives

[0104]

[0105] where ε0 is the initial value of ε.

[0106] Taking the derivative of Equation (24), we get

[0107]

[0108] From Equation (25), it can be seen that the variable μ should first satisfy μ > 1 to ensure that the amplitudes of the angular deviation term and its rate of change will gradually converge to zero over time.

[0109] In addition, for the problem of impact with a constrained fall angle, generally two tasks need to be completed simultaneously: First, ensure that the loitering munition hits the target; Second, ensure that the ballistic inclination angle at the time of hitting the target is equal to the expected value. Therefore, the state variables can be taken as

[0110]

[0111] The state variable x1 represents the angular deviation feedback term ε, and the state variable x2 represents the line-of-sight angular rate. When x1 → 0, it indicates that the angle control is basically completed; when x2 → 0, the loitering munition will hit the target. Taking the derivative of Equation (26) with respect to time t and approximately assuming we obtain the state equations for x1 and x2 as

[0112]

[0113] Analysis shows that this is a non-homogeneous linear differential equation system with variable coefficients. Construct the Lyapunov candidate function in the following form

[0114]

[0115] where and are both positive constants.

[0116] Taking the derivative of Equation (28) with respect to time t, letting and ensuring we can take in the following form

[0117]

[0118] Comparing equations (22) and (29) and making the coefficients of the first terms in the two equations equal, we can obtain k = N D -2. Substituting k into the coefficient of the second term in equation (29) and after rearrangement, we can get

[0119] μ = (N D -1) / (m + 1) (30)

[0120] In the process of deriving the bias proportional guidance algorithm, the angular deviation weight coefficient μ can be used to coordinate the weight relationship between the proportional guidance command and the angle control command, which will directly affect the angle and miss distance control performance of this guidance algorithm. The variable μ should be within a reasonable range throughout the guidance stage. The main reasons are as follows: 1) If the amplitude of the variable μ is too large, the angle control command will have a relatively obvious impact on the proportional guidance command, which is very likely to reduce the control accuracy of the miss distance; 2) When constructing the guidance algorithm, the small deviation assumption is adopted, and there will be certain deviations to a certain extent. If the variable μ is too large, these errors will also be amplified, thus affecting the convergence of the algorithm; 3) If the value of the variable μ is too small, the angle control term cannot converge in time, which will affect the fall angle control accuracy.

[0121] The variable μ should first satisfy μ > 1, which can ensure that the amplitude of the angular deviation term and the amplitude of its change rate will gradually converge to zero over time. In addition, for the problem of strike with fall angle constraint, generally two tasks need to be completed simultaneously: First, ensure that the loitering munition hits the target; Second, ensure that the ballistic inclination angle at the time of hitting the target is equal to the expected value. Based on the above analysis, the selection principle of the angular deviation weight coefficient μ is as follows: First, to ensure the convergence of the angle control term, especially in the middle and later stages of the trajectory, it is necessary to ensure that the value of m can ensure μ ∈ (1, N D -1); Second, the angle control command is mainly achieved by stretching the trajectory, which is restricted by the field of view of the seeker. The trajectory adjustment is mainly carried out in the first half of the trajectory. If the loitering munition is about to exceed the field of view constraint during the directional strike process, m can be adjusted to make μ ≤ 1 to ensure that the target is always within the field of view of the loitering munition.

[0122] For the longitudinal plane time estimation, a remaining time estimation method for stationary targets is used, and its specific form is as follows:

[0123]

[0124] In the formula, η D = θ + φ is the lead angle. Combining with equation (22), we get

[0125]

[0126] In the longitudinal plane, the line-of-sight elevation angle rate can be approximately expressed as

[0127]

[0128] Among them, r is the relative distance between the loitering munition and the target, and its rate of change is

[0129]

[0130] Approximately considered Then Equation (32) can be approximately expressed as

[0131]

[0132] By combining Equation (34) and (35), the estimated value of η D is

[0133]

[0134] Among them,

[0135]

[0136] The accuracy of the remaining time estimation method is directly related to the guidance method adopted. The remaining time estimation method obtained from Equation (31) only considers the influence of the proportional command term on the remaining time estimation, and does not consider the influence effect of the angle control term on the remaining time estimation. Substituting Equation (37) into Equation (31) and after arrangement, the estimation formula of the proportional term for the remaining time can be obtained as

[0137]

[0138] For the guidance method adopted in the present invention, the direct influence of the bias term on the remaining time should also be considered. For a stationary target, the influence amplitude of the bias term on the ballistic length is

[0139]

[0140] Substitute a PN,D and a B,D into Equation (40), and after arrangement, it can be obtained as

[0141]

[0142] Using Equation (43), the expression of the remaining time t goD,B caused by the bias term can be calculated through t goD,B / V M and its specific form after arrangement is

[0143]

[0144] Finally, the specific expression of the total remaining time in the longitudinal plane with respect to the angular deviation term is

[0145] tgoD = t goD,PN + t goD,B (45)

[0146] In equation (45), it is the longitudinal plane time estimation method after comprehensively considering the proportional term and the angle control term.

[0147] II. Time Control and Cooperative Strike Strategy

[0148] 1. With Time-Constrained Biased Proportional Guidance

[0149] When designing the time control and cooperative strike strategy, design the motion equation of the loitering munition in the lateral plane. The geometric relationship of the lateral plane motion is as Figure 3 shown.

[0150] Define Ψ as the line-of-sight azimuth angle, then the lead angle η in the lateral plane L can be expressed as

[0151] η L = ψ - Ψ (46)

[0152] According to the geometric relationship in the dive plane, it can be obtained that

[0153]

[0154] In the formula, s is the projection of the line connecting the missile and the target in the lateral plane, and V MT is the projection of the loitering munition speed on the horizontal plane, and its magnitude is V MT = V M cosθ.

[0155] For the lateral plane, based on the biased proportional form, the guidance law form can be expressed as the following form:

[0156] a ML = a PNL + a BL (48)

[0157] Among them, a PNL is the proportional command term in the lateral plane. Usually N L is the lateral plane guidance coefficient; a BL is the bias term (or called the time control term) of the lateral plane guidance law, which provides the time control command.

[0158] For the time control term in equation (48), it can be given by the following formula

[0159] a BL = Γ L sV M ξ(t) In formula (51), the gain parameter Γ LThe time deviation ξ(t) can be respectively given by the following equations

[0160]

[0161] ξ(t) = T d -t - t goL (53)

[0162] where k L1 and k L2 are two correction coefficients, T d is the expected arrival time, and t goL is the remaining time in the lateral plane. The remaining time t goL can be given by the following equation

[0163]

[0164] 2. Remaining Time Coordination Estimation Strategy

[0165] To conduct time control, the flight path of the loitering munition is stretched relative to the reference flight path (proportional navigation flight path), and the arrival time of the loitering munition at the target is changed by adjusting the length of the flight path. In the longitudinal plane, the loitering munition mainly conducts targeted strikes on the target and itself needs to adjust the flight path. If a time control term is added, it will surely affect the impact angle control accuracy. In addition, in the terminal guidance stage, the dynamic performance of the loitering munition will decline significantly. A large maneuver in the longitudinal plane is usually not conducive to the normal flight of the loitering munition, and the loitering munition is mostly a symmetric aircraft with strong lateral maneuverability. Therefore, it is necessary to decouple the impact angle control and time control as much as possible to avoid mutual interference between the two. Only impact angle control is carried out in the longitudinal plane so that the loitering munition can hit the target with the expected attitude. In the lateral plane, time control is mainly carried out, and the arrival time is adjusted by stretching the flight path to the left or right. Based on the above analysis, the remaining time estimation formula designed this time is

[0166] t go = (1 - ω)·t goD + ω·t goL (55)

[0167] where ω ∈ [0, 1] is a weight coefficient, The designed remaining time estimation equation mainly consists of two parts: the first part is the estimated value of the remaining time in the lateral direction of the longitudinal plane; the second part is the estimated value of the remaining time in the lateral plane. In the initial stage of terminal guidance, the angle control command is relatively small. At this time, the arrival time is mainly adjusted by lateral deflection. Since the lateral lead angle is relatively large, the estimated value of the remaining time in the lateral plane is used. As the loitering munition approaches the target, that is, ω increases, the lateral plane gradually converges, and the angle control command gradually increases. The longitudinal lead angle will gradually increase at the beginning, and the estimated value of the remaining time in the longitudinal plane is used.

[0168] 3. Cooperative Strike Strategy

[0169] To solve the problem of achieving distributed cooperative guidance time consistency using a time-constrained terminal guidance law in the case of topological jumps in the formation support network, a two-layer cooperative guidance control structure is adopted, as shown in Figure 5 Figure [not provided]. The upper-layer cooperative strategy uses a distributed weighted average consensus algorithm, which calculates the expected guidance time of the loitering munition formation based on the expected guidance times provided by each loitering munition. The lower-layer guidance law with time and impact angle constraints guides and controls each member according to the obtained expected guidance time of the loitering munition formation, and hits the target simultaneously with a given impact angle.

[0170] Suppose there are n loitering munitions participating in the cooperative attack and they are required to hit the target simultaneously. The local guidance law has a "controllable quantity", namely the expected guidance time t goi (representing the i-th loitering munition). Therefore, the coordination variable ξ is taken as the expected guidance time t goi . By taking the distributed weighted average consensus algorithm and the time guidance law corresponding to Equation (48), the coordinated expected guidance time can be obtained as

[0171]

[0172] where

[0173] α i = Γ L,i s i (57)

[0174] t go,i = (1 - ω i )·t goD,i + ω i ·t goL,i (58)

[0175] The variable α i is the weight coefficient of the time control term. Although the variable ξ * is not strictly the optimal solution, its physical meaning is very obvious: the value of the expected guidance time obtained through negotiation is the weighted average of the remaining time estimates of each loitering munition. Based on the above design and analysis, during the cooperative strike process, the i-th loitering munition needs to transmit the information required for cooperation (α i , t go,i ) to the cooperative control device. The cooperative control device obtains the sub-optimal value of the coordination variable according to the coordination algorithm Equation (56), and then broadcasts it to all loitering munition members within the swarm formation. After each member receives the unified coordination variable value, it can obtain its guidance control quantity according to the local guidance law, and the entire loitering munition formation completes the cooperative task under the control of decentralized guidance control and hits the target simultaneously. The algorithm structure is as shown in Figure 5as shown

[0176] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A method for cooperative terminal strike of loitering munitions based on impact angle and time constraints, characterized in that The steps are as follows: Step 1: Each loitering munition estimates the remaining time to reach the target using the local guidance law and the time control term weight coefficient , and sends them to the cooperative control device of the leading munition in the loitering munition formation; The remaining time : In the formula, is a weight coefficient; is the longitudinal plane remaining time estimate value, and its expression is: Wherein, is the relative distance between the loitering munition and the target, is the desired missile-to-target distance, is the square of the desired lead angle, is the angular deviation weight coefficient, is the flight speed, is the longitudinal plane guidance coefficient; is the line-of-sight elevation angle, is the ballistic inclination angle, is the angular deviation weight coefficient, is the angular deviation; is the estimation of the remaining time by the example item, is the remaining time caused by the offset term; is the remaining time of the lateral plane guidance law, and its expression is: In the formula, is the lateral plane guidance coefficient, is the projection of the missile-target line in the lateral plane, is the projection of the loitering missile speed on the horizontal plane, is the square of the lead angle in the turning plane; Step 2: The cooperative control device calculates the expected remaining time of the loitering munition formation using the distributed weighted average consensus algorithm ; Among them, is the remaining time for the i th loitering munition to reach the target, n is the total number of loitering munitions; is the time control item weight coefficient of the i th loitering munition; Step 3: Expected remaining time after lead-follow collaborative calculation Broadcast to all loitering munition members within the swarm formation. After each member receives the unified expected remaining time it calculates the guidance control quantity according to the local guidance law. The entire loitering munition formation completes the collaborative mission under the control of decentralized guidance control and hits the target simultaneously.

2. The end - coordinated strike method of the loitering munition based on impact angle and time constraint according to claim 1, wherein: The local guidance law described in step 3 includes a longitudinal plane guidance law and a lateral plane guidance law, and the expression of the longitudinal plane guidance law is: Among them, is the longitudinal plane ratio command item, is the offset item of the longitudinal plane guidance law, is the angular deviation; The expression of the lateral plane guidance law is: Among them, is the lateral plane ratio command item, is the bias term of the lateral plane guidance law.

3. A computer system, characterized in that including: One or more processors, a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method described in claim 1.

4. A computer-readable storage medium, characterized in that Stored with computer-executable instructions, the instructions are used to implement the method described in claim 1 when executed.

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