Control input limited patrol missile cluster distributed time cooperative guidance method

Abstract

The invention discloses a distributed time cooperative guidance method for a patrol missile cluster with limited control input, and belongs to the technical field of patrol missile cluster guidance control. Establishing a double-layer collaborative guidance framework of the patrol missile cluster; the individuals take the residual flight time estimation values as coordination variables, the respective residual flight time estimation values are interacted through communication among the projectiles, and expected coordination variable values of all the projectiles are obtained through coordination strategy calculation and serve as input of a lower-layer time constraint guidance law; decomposing a lower-layer time constraint guidance law into a transverse lateral plane and a longitudinal plane, calculating an attitude angle and an accelerator through a segmented guidance law, and inputting the attitude angle and the accelerator as guidance control variables into the autopilot; according to an input attitude angle and an accelerator instruction, obtaining a rudder amount and an accelerator amount, and controlling the attitude and the speed of the patrolling bomb to realize time coordination. The invention provides a distributed time cooperative guidance method for a patrolling bomb cluster with limited control input, and aims to solve the problem that the patrolling bomb cluster simultaneously strikes a stationary target on the ground when the control input is limited to an attitude angle and an accelerator.

Description

Technical Field

[0001] The present invention relates to the technical field of cruise missile cluster guidance control, and in particular to a cruise missile cluster distributed time collaborative guidance method with limited control input. Background Art

[0002] Cruise missiles are ammunition with the characteristics of drones, with both hovering cruise and guided strike capabilities. Multiple cruise missiles can effectively improve combat effectiveness by leveraging group advantages through collaborative operations. According to the terminal constraint condition of time or angle, collaborative guidance can be divided into time coordination, space coordination and space-time coordination. Spatial coordination is mostly open-loop coordination with pre-bound attack angle constraints, and closed-loop space coordination with information interaction between individuals is often combined with time coordination to achieve space-time coordination. Therefore, in the multi-missile collaborative guidance scenario, time is the most basic constraint. For a single target, the simultaneous attack of a cruise missile cluster can saturate the target's defense system in a short time and increase the probability of penetration; for multiple targets, the simultaneous attack of a cruise missile cluster can prevent some targets from maneuvering and escaping, achieving "one net catch".

[0003] Time coordinated guidance method is the key technology to achieve simultaneous strike. Common time coordinated guidance methods can be divided into two categories: open-loop coordinated guidance and closed-loop coordinated guidance according to whether there is communication between missiles.

[0004] Open-loop collaborative guidance requires setting the attack time in advance, and time constraints are often introduced based on the following two control methods: (1) biased proportional guidance law, which adds a time error feedback term on the basis of the proportional guidance law. (2) sliding mode control, which designs the time error of the sliding mode surface to be 0 to make the motion state converge.

[0005] Closed-loop collaborative guidance is the process of each missile communicating to achieve coordination and consistency during the guidance process. According to whether there is a centralized coordination unit in the communication topology, closed-loop collaborative guidance can be divided into centralized coordination and distributed coordination. Compared with centralized coordination, distributed coordination requires less information, has stronger cluster robustness, and is conducive to cluster expansion. In a real battlefield environment, it is difficult to obtain enemy target information before the battle. The distributed coordination strategy coordinates the strike time in real time, avoiding the preset strike time.

[0006] Most traditional time-coordinated guidance methods do not consider the input limitations of the autopilot, and only use acceleration as the control input of the autopilot in the guidance loop design. Due to the error in the remaining flight time estimation, the time adjustable range of traditional time-coordinated guidance methods based on the remaining flight time is small. Summary of the invention

[0007] The purpose of the present invention is to provide a distributed time cooperative guidance method for a cruise missile cluster with limited control input to solve the problems existing in the background technology.

[0008] To achieve the above object, the present invention provides a method for distributed time coordinated guidance of a cruise missile cluster with limited control input, comprising the following steps:

[0009] S1. Establish a two-layer collaborative guidance architecture for cruise missile clusters, and implement segmented guidance in the lateral and longitudinal planes. The two-layer refers to the decomposition of the collaborative guidance algorithm into an upper-layer coordination strategy and a lower-layer time-constrained guidance law; it also refers to the collaborative guidance algorithm layer and the cruise missile autopilot control layer.

[0010] S2. Cruise missiles estimate the remaining flight time before hitting the target based on their own posture information. Cruise missiles communicate with each other to exchange their respective estimated remaining flight time values. The coordination strategy calculates the expected coordination variable value for each missile, which serves as the input of the lateral three-stage coordinated guidance law and the longitudinal two-stage coordinated guidance law.

[0011] S3. The biased proportional guidance law is used in the lateral direction, and the lead angle limitation mechanism is used to reduce the remaining flight time estimation error; the longitudinal guidance is decomposed into level flight and dive segments, using the total energy control theory and the integral proportional guidance law respectively, and the level flight to dive switching criterion is used to achieve fine-tuning of the time error; the attitude angle and throttle command are obtained through the attitude mapping method as the control input of the autopilot.

[0012] S4. The inner loop of the cruise missile autopilot obtains the steering amount and throttle amount according to the input attitude angle and throttle command, and controls the attitude and speed of the cruise missile to achieve time coordination.

[0013] Preferably, the double-layer collaborative guidance architecture is applied in the lateral plane and the longitudinal plane respectively.

[0014] Preferably, a three-stage lateral and lateral coordinated guidance law is designed for the lateral plane, including an offset proportional guidance section, a lead angle limiting section and a pure proportional guidance section. The offset proportional guidance section process is as follows:

[0015] Specify the cruise missile hit time as T d , the cruise missile has flown for t and has a remaining flight time of t go , then the cruise missile's hit time error e t It is expressed as:

[0016] e t =T d -tt go ;

[0017] When each cruise missile hits the target t Equal to 0, to achieve the same specified hit time T d Hit the target;

[0018] The bias proportional guidance law expression with time error feedback term is:

[0019] a ITCG =a PNG +Ke t ;

[0020] in, It is a pure proportional guidance law; is the gain coefficient; V is the cruise missile velocity vector, N is the navigation ratio, and R is the missile-target distance;

[0021] The biased proportional guidance law is proposed based on the estimated remaining flight time. The remaining time t go The estimation method is as follows:

[0022]

[0023] Where η is the velocity vector lead angle.

[0024] Preferably, the leading angle limiting stage process is as follows:

[0025] Limit the leading deflection angle to satisfy η h ≤η M ,η M ∈[60°,90°], the rate of change of the leading deflection angle is expressed as:

[0026]

[0027] Among them, R xy 、V xy 、a xy are the relative distance between the missile and the target, the velocity vector of the cruise missile, and the projection of the normal acceleration in the lateral plane; ψ, λ h , η h They are the yaw angle, the missile-eye line of sight deflection angle and the leading deflection angle;

[0028] When the lead deflection angle increases to the upper limit range, the rate of change of the lead deflection angle is set to 0, so that the lead deflection angle no longer increases. The normal acceleration at this time is expressed as:

[0029]

[0030] When the time error e t When it converges to 0, the guidance law is switched to pure proportional guidance law;

[0031] The inner loop input of the cruise missile autopilot is attitude and throttle. The normal acceleration obtained in the lateral direction is converted into attitude angle through attitude mapping. The cruise missile adopts tilt turning control, and the normal acceleration is mapped into a rolling instruction expressed as:

[0032]

[0033] Preferably, a longitudinal two-stage cooperative guidance law is designed for the longitudinal plane, including a level flight coordination section and a dive section. The level flight coordination section is before the cruise missile enters a dive, and the time error is coordinated by increasing the track under the control of the lateral cooperative guidance law. The remaining time estimation method adopted assumes that the cruise missile speed is constant, and the total energy control theory is used to decouple the altitude and speed control, the throttle is used to control the rate of change of the total energy, and the elevator is used to coordinate the conversion between kinetic energy and potential energy.

[0034] Preferably, the dive phase process is as follows: in the dive phase, the cruise missile rapidly reduces its altitude by controlling the pitch angle and dives toward the target; integrating both sides of the pure proportional guidance law expression, the pure proportional guidance law in integral form is expressed as:

[0035]

[0036] in is the initial value of the line of sight inclination angle when the cruise missile enters a dive; θ0 is the initial value of the pitch angle when entering a dive; the proportional guidance law in integral form guides the cruise missile to the target.

[0037] Preferably, the longitudinal plane also includes a level flight to dive switching criterion, which is as follows:

[0038] The necessary condition for entering a dive is that the line of sight angle converges to a smaller value, expressed as:

[0039] λ hi <ε1;

[0040] The sight angles of cruise missiles at different altitudes and missile-target distances are different. In order to achieve that the cruise missiles with higher altitudes enter the dive earlier, the switching criterion is expressed as:

[0041] λ vi <ε2;

[0042] When both equations are satisfied at the same time, the switching criterion for level flight to dive is obtained.

[0043] Preferably, the cooperative guidance laws in the lateral plane and the longitudinal plane are combined to obtain the lower-level time-constrained guidance law. A distributed coordination strategy is designed according to the specified hit time in the lateral cooperative guidance law to obtain a coordinated hit time to replace the specified hit time T d , the content is as follows:

[0044] The distributed coordination strategy assumes that each missile can obtain the estimated value of the remaining flight time of the adjacent individuals, and increases the weight of the individuals with longer remaining flight time by weighted average method, so that the coordination time t go,i (t) satisfies the individual hit time range [T min ,T max ], the distributed coordination strategy is:

[0045]

[0046] Among them, S i represents the communication topology of cruise missile i; s j represents the number of cruise missiles in its communication topology; k j Represents weight.

[0047] Therefore, the present invention adopts the above-mentioned cruise missile cluster distributed time cooperative guidance method with limited control input, which has the following beneficial effects:

[0048] (1) The present invention adds autopilot model constraints to obtain attitude angle and throttle as control inputs of the attitude autopilot, satisfying the input restrictions of the tandem wing cruise missile autopilot;

[0049] (2) The distributed coordination strategy coordinates the strike time in real time, avoiding the preset strike time. The present invention adopts a weighted average method to obtain the distributed coordination strategy, so that the coordinated consensus time meets the lower limit of the adjustable range of the cruise missile flight time.

[0050] (3) Based on the concept of segmented guidance, the present invention designs a lead angle limitation mechanism to reduce the remaining flight time estimation error and improve the algorithm adaptability.

[0051] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a flow chart of a distributed time cooperative guidance method for a cruise missile cluster with limited control input according to the present invention;

[0053] Figure 2 Schematic diagram of a double-layer collaborative guidance architecture in an embodiment of the present invention;

[0054] Figure 3 This is a flow chart of the three-stage lateral coordinated guidance law according to an embodiment of the present invention;

[0055] Figure 4 This is a flow chart of the lower-level time-constrained guidance law according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] Distributed collaborative guidance algorithms usually build a coordination layer on top of the open-loop collaborative guidance algorithm and apply modern control theory to design collaborative control strategies. According to the different coordination variables, it can be divided into the following collaborative methods: (1) Coordination of remaining flight time. On the basis of estimating the remaining flight time, the control method is designed to coordinate the estimated values ​​of the remaining flight time of each missile. (2) Coordination of missile-target distance. The problem of estimating the remaining flight time is transformed into a problem of consistency between the missile and the target, which avoids the error of the remaining flight time estimation. Most of them assume that the speed of each missile is a constant. (3) Coordination of speed. On the basis of path planning, the speed of each missile is coordinated to achieve coordination.

[0058] Most existing methods use acceleration as the control command input to the autopilot, without considering the input limit of the autopilot. Cruise missiles have both hovering cruise and guided strike capabilities. To maintain their stable flight, they often use attitude autopilots. The input limits of their autopilots are attitude angle and throttle. It is necessary to design a time-coordinated guidance algorithm that meets the input limits in combination with flight characteristics.

[0059] See also Figure 1 , a distributed time cooperative guidance method for a cruise missile cluster with limited control input, comprising the following steps:

[0060] S1. Establish a two-layer collaborative guidance architecture for cruise missile clusters, as shown in the attached Figure 2 As shown. The "double layer" of the collaborative guidance architecture described in this embodiment has two meanings. In algorithm design, "double layer" refers to the decomposition of the collaborative guidance algorithm into an upper-layer coordination strategy and a lower-layer time-constrained guidance law; in control implementation, "double layer" refers to the collaborative guidance algorithm layer and the cruise missile autopilot control layer, which correspond to the guidance loop and the control loop respectively.

[0061] S2. Cruise missiles estimate the remaining flight time before hitting the target based on their own posture information. Cruise missiles communicate with each other to exchange their respective estimated remaining flight time values. The coordination strategy calculates the expected coordination variable value for each missile, which serves as the input of the lateral three-stage coordinated guidance law and the longitudinal two-stage coordinated guidance law.

[0062] S3. The biased proportional guidance law is used in the lateral direction, and the lead angle limitation mechanism is used to reduce the remaining flight time estimation error; the longitudinal guidance is decomposed into level flight and dive segments, using the total energy control theory and the integral proportional guidance law respectively, and the level flight to dive switching criterion is used to achieve fine-tuning of the time error; the attitude angle and throttle command are obtained through the attitude mapping method as the control input of the autopilot.

[0063] S4. The inner loop of the cruise missile autopilot obtains the steering amount and throttle amount according to the input attitude angle and throttle command, and controls the attitude and speed of the cruise missile to achieve time coordination.

[0064] This embodiment mainly summarizes the dual-layer cooperative guidance architecture from the perspective of control implementation. In view of the input limitations of the cruise missile attitude driver, the cruise missile time cooperative guidance problem in three-dimensional space is decoupled into the lateral and longitudinal planes, and the remaining flight time estimate is used as the coordination variable to implement the distributed time cooperative guidance algorithm. The algorithms in the two planes are described in detail below.

[0065] Laterally and upward, the cruise missile estimates the individual remaining flight time based on the missile-target line of sight angle, obtains the estimated value of the remaining flight time of the adjacent individuals through the communication network, obtains the expected remaining flight time through the distributed coordination strategy, and calculates the individual time error.

[0066] Furthermore, under the control of the biased proportional guidance law with a time error feedback term, the flight time is coordinated by coordinating the flight track. When the lead angle increases to the limit value, the cruise missile flies with a constant normal acceleration to keep the lead angle near the maximum value to ensure the accuracy of time estimation. When the time error converges, the cruise missile hits the target under the control of the proportional guidance law. The above controls all calculate the normal acceleration, and the roll angle command is obtained through the attitude mapping method as the input of the cruise missile autopilot.

[0067] (1) Lateral three-stage coordinated guidance law

[0068] In this embodiment, the cruise missile hit time is specified as T d , the cruise missile has flown for t and has a remaining flight time of t go , then the cruise missile's hit time error e t It can be expressed as:

[0069] e t =T d -tt go ;

[0070] When each cruise missile hits the target t Equal to 0, to achieve the same specified time T d Hit the target.

[0071] The proportional guidance law is simple in form and easy to implement in engineering. The bias proportional guidance law with time error feedback term is expressed as:

[0072] a ITCG =a PNG +Ke t ;

[0073] in, It is a pure proportional guidance law. is the gain coefficient, V is the cruise missile velocity vector, N is the navigation ratio, and R is the missile-target distance.

[0074] The above biased proportional guidance law is proposed based on the estimated remaining flight time. The remaining time t go The estimation method of is as follows, where η is the velocity vector lead angle.

[0075]

[0076] This remaining time estimation method is obtained under the small angle assumption, that is, the smaller the velocity vector lead angle, the higher the estimation accuracy. After adjustment in the mid-guidance stage, the initial velocity vector lead angle of the cruise missile is generally small when it enters the terminal guidance stage. However, in the coordination process, it is necessary to coordinate the remaining flight time by increasing the flight track, so a large lead angle may still occur. In order to avoid the occurrence of a large lead angle during the coordination process, resulting in inaccurate estimated time and coordination failure, this embodiment designs a lead angle limitation mechanism.

[0077] Limit the leading deflection angle to satisfy η h ≤η M ,η M ∈[60°,90°]. The rate of change of the leading deflection angle is expressed as:

[0078]

[0079] Among them, R xy 、V xy 、a xy are the relative distance between the missile and the target, the velocity vector of the cruise missile, and the projection of the normal acceleration in the lateral plane, ψ, λ h , η h They are the yaw angle, the missile-target line of sight deviation angle and the lead deviation angle respectively.

[0080] When the lead deflection angle increases to the upper limit range, the lead deflection angle change rate is set to 0, thereby controlling the lead deflection angle to not continue to increase. The normal acceleration at this time is expressed as:

[0081]

[0082] In addition, in order to ensure accurate strike on the target, when the time error e t When it converges to 0, the guidance law is switched to the proportional guidance law.

[0083] The input of the inner loop of the cruise missile autopilot is attitude and throttle, so the normal acceleration obtained in the lateral direction needs to be converted into attitude angle through attitude mapping. The cruise missile adopts bank turning control, and the normal acceleration is mapped into a rolling instruction as follows:

[0084]

[0085] Therefore, this embodiment designs a three-stage time coordinated guidance algorithm for the lateral direction as shown in the attached figure. Figure 3The lateral open-loop collaborative guidance algorithm includes a bias proportional guidance section, a lead angle limiting section, and a pure proportional guidance section.

[0086] In the offset proportional guidance section, the lead deviation angle is less than the maximum lead deviation angle limit. The cruise missile moves away from the target under the control of the offset proportional guidance law, and the flight time is coordinated by increasing the flight track. During this process, the lead deviation angle of the cruise missile gradually increases.

[0087] When the lead angle of the cruise missile increases to its maximum value, it enters the lead angle limitation section. The cruise missile maintains a constant normal acceleration and flies along a logarithmic spiral curve, and the lead angle no longer increases.

[0088] When the calculated time error converges, it enters the proportional guidance stage. The cruise missile switches to the proportional guidance law, the lead angle decreases, and flies towards the target.

[0089] In the vertical direction, it is divided into the level flight stage and the dive stage according to whether the cruise missile enters a dive. In the level flight stage, according to the total energy control theory, the altitude and speed control are decoupled to obtain the pitch angle and throttle command to maintain the stable level flight of the cruise missile. The switching criteria for level flight to dive are designed according to the lead deflection angle and the lead inclination angle, so that the higher the altitude of the cruise missile, the earlier it enters a dive. When the switching criteria are met, it enters a dive. In the dive stage, the integral proportional guidance is used to directly obtain the pitch angle command.

[0090] (2) Longitudinal two-stage coordinated guidance law

[0091] According to whether the cruise missile enters a dive, this embodiment divides the longitudinal coordinated guidance law into a level flight coordination section and a dive section.

[0092] 1. Level flight coordination phase: Before the cruise missile enters the dive, the time error is coordinated by increasing the track under the control of the lateral coordinated guidance law. The remaining time estimation method adopted assumes that the cruise missile speed is constant. Therefore, in order to ensure the accuracy of the remaining time estimation during the coordination process, the speed of the cruise missile needs to be maintained as much as possible. The total energy control theory is used to decouple the altitude and speed control. The core idea is to use the throttle to control the rate of change of the total energy and use the elevator to coordinate the conversion between kinetic energy and potential energy.

[0093] 2. Dive phase: In the dive phase, the cruise missile quickly reduces its altitude by controlling the pitch angle and dives towards the target. Integrating both sides of the proportional guidance law expression, the proportional guidance law in integral form is expressed as:

[0094]

[0095] in is the initial value of the line of sight angle when the cruise missile enters a dive, and θ0 is the initial value of the pitch angle when entering a dive. The proportional guidance law in integral form guides the cruise missile to the target.

[0096] 3. "Level flight to dive" switching criteria: Different cruise missiles have different initial altitudes when entering the dive phase. This embodiment designs the switching criteria for switching from the level flight phase to the dive phase to meet the coordination of cruise missiles in the dive phase. To ensure guidance accuracy, the necessary condition for entering the dive is that the line of sight deflection angle converges to a smaller value, which can be expressed as:

[0097] λ hi <ε1;

[0098] The sight angles of cruise missiles at different altitudes and missile-target distances are different. In order to achieve the earlier entry of the cruise missile into the dive at higher altitudes, the switching criterion can be expressed as:

[0099] λ vi <ε2;

[0100] When the above two equations are satisfied at the same time, the switching criterion from level flight to dive is obtained.

[0101] Combining the cooperative guidance laws in the lateral plane and the longitudinal plane, we can obtain the lower-level time-constrained guidance law as shown in the attached figure. Figure 4 As shown in the figure. The lateral and lateral directions are coordinated by the bias proportional guidance law. When the time error e t When it converges to 0, it switches to the proportional guidance law; in the longitudinal direction, the speed and altitude of the cruise missile are maintained by the total energy control theory in the level flight phase. When the switching criteria are met, the cruise missile enters a dive, and in the dive phase, the cruise missile is guided to the target by the integral proportional guidance law.

[0102] In actual combat, the actual hit time is often unpredictable. Therefore, this embodiment designs a distributed coordination strategy to obtain a coordinated hit time to replace the specified hit time T d .

[0103] The distributed coordination strategy assumes that each missile can only obtain the estimated remaining flight time of its neighboring individuals. By using the weighted average method, the weight of the individual with a larger remaining flight time is increased, so that the coordination time t go,i (t) Try to meet the individual hit time range [T min ,T max ]. The distributed coordination strategy is:

[0104]

[0105] Where S i represents the communication topology of cruise missile i, s j represents the number of cruise missiles in its communication topology, k j Represents weight.

[0106] Finally, the inner loop of the cruise missile autopilot obtains the steering amount and throttle amount according to the input attitude angle and throttle command, and controls the attitude and speed of the cruise missile to achieve time coordination.

[0107] Therefore, the present invention adopts the above-mentioned distributed time collaborative guidance method for a cruise missile cluster with limited control input, and adopts a weighted average method to obtain a distributed coordination strategy, so that the coordinated consistency time meets the lower limit of the adjustable range of the cruise missile flight time, reduces the remaining flight time estimation error, and improves the adaptability of the algorithm.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A distributed time cooperative guidance method for a cruise missile cluster with limited control input, characterized in that: The following steps are involved: S1. Establish a two-layer collaborative guidance architecture for cruise missile clusters, and implement segmented guidance in the lateral and longitudinal planes respectively; two-layer refers to the decomposition of the collaborative guidance algorithm into an upper-layer coordination strategy and a lower-layer time-constrained guidance law; it also refers to the collaborative guidance algorithm layer and the cruise missile autopilot control layer; S2. The individual cruise missiles estimate the remaining flight time before hitting the target based on their own posture information. The cruise missiles communicate with each other to exchange their respective estimated remaining flight time values. The coordination strategy calculates the expected coordination variable value of each missile as the input of the lateral three-stage coordinated guidance law and the longitudinal two-stage coordinated guidance law. S3, the biased proportional guidance law is used in the lateral direction, and the error of the remaining flight time estimation is reduced through the lead angle limitation mechanism; the longitudinal guidance is decomposed into the level flight and dive sections, and the total energy control theory and the integral proportional guidance law are used respectively, and the time error is fine-tuned through the level flight to dive switching criterion; the attitude angle and throttle command are obtained as the control input of the autopilot through the attitude mapping method; S4. The inner loop of the cruise missile autopilot obtains the steering amount and throttle amount according to the input attitude angle and throttle command, and controls the attitude and speed of the cruise missile to achieve time coordination.

2. The method for distributed time-coordinated guidance of cruise missile clusters with limited control input according to claim 1, characterized in that: The double-layer collaborative guidance architecture is applied in the lateral plane and the longitudinal plane respectively.

3. The method for distributed time-coordinated guidance of cruise missile clusters with limited control input according to claim 2, characterized in that: A three-stage lateral and lateral coordinated guidance law is designed for the lateral plane, including the offset proportional guidance section, the lead angle limitation section and the pure proportional guidance section. The offset proportional guidance section process is as follows: Specify the cruise missile hit time as T d , the cruise missile has flown for t and has a remaining flight time of t go , then the cruise missile's hit time error e t It is expressed as: e t =T d -t-t go ; When each cruise missile hits the target t Equal to 0, to achieve the same specified hit time T d Hit the target; The bias proportional guidance law expression with time error feedback term is: a ITCG =a PNG +Ke t ; in, It is a pure proportional guidance law; is the gain coefficient; V is the cruise missile velocity vector, N is the navigation ratio, and R is the missile-target distance; The biased proportional guidance law is proposed based on the estimated remaining flight time. The remaining time t go The estimation method is as follows: Where η is the velocity vector lead angle.

4. The method for distributed time-coordinated guidance of cruise missile clusters with limited control input according to claim 3 is characterized in that: The lead angle limiting process is as follows: Limit the leading deflection angle to satisfy η h ≤η M ,η M ∈[60°,90°], the rate of change of the leading deflection angle is expressed as: Among them, R xy 、V xy 、a xy are the relative distance between the missile and the target, the velocity vector of the cruise missile, and the projection of the normal acceleration in the lateral plane; ψ, λ h , η h They are the yaw angle, the missile-eye line of sight deflection angle and the leading deflection angle; When the lead deflection angle increases to the upper limit range, the rate of change of the lead deflection angle is set to 0, so that the lead deflection angle no longer increases. The normal acceleration at this time is expressed as: When the time error e t When it converges to 0, the guidance law is switched to pure proportional guidance law; The inner loop input of the cruise missile autopilot is attitude and throttle. The normal acceleration obtained in the lateral direction is converted into attitude angle through attitude mapping. The cruise missile adopts tilt turning control, and the normal acceleration is mapped into a rolling instruction expressed as:

5. The method for distributed time-coordinated guidance of cruise missile clusters with limited control input according to claim 4, characterized in that: A two-stage longitudinal cooperative guidance law is designed for the longitudinal plane, including the level flight coordination stage and the dive stage. The level flight coordination stage is before the cruise missile enters the dive, and the time error is coordinated by increasing the track under the control of the lateral cooperative guidance law. The remaining time estimation method adopted assumes that the cruise missile speed is constant, and the total energy control theory is used to decouple the altitude and speed control. The throttle is used to control the rate of change of total energy, and the elevator is used to coordinate the conversion between kinetic energy and potential energy.

6. The method for distributed time-coordinated guidance of cruise missile clusters with limited control input according to claim 5, characterized in that: The process of the dive phase is as follows: In the dive phase, the cruise missile quickly reduces its altitude by controlling the pitch angle and dives toward the target; integrating both sides of the pure proportional guidance law expression, the pure proportional guidance law in integral form is expressed as: in is the initial value of the line of sight inclination angle when the cruise missile enters a dive; θ0 is the initial value of the pitch angle when entering a dive.

7. The method for distributed time-coordinated guidance of cruise missile clusters with limited control input according to claim 6, characterized in that: The longitudinal plane also includes the transition criteria from level flight to dive, which are as follows: The necessary condition for entering a dive is that the line of sight angle converges to a smaller value, expressed as: l hi <e1; The sight angles of cruise missiles at different altitudes and missile-target distances are different. In order to achieve that the cruise missiles with higher altitudes enter the dive earlier, the switching criterion is expressed as: l vi <e2; When both equations are satisfied at the same time, the switching criterion for level flight to dive is obtained.

8. The method for distributed time-coordinated guidance of cruise missile clusters with limited control input according to claim 7, characterized in that: The cooperative guidance laws in the lateral plane and the longitudinal plane are combined to obtain the lower-level time-constrained guidance law. According to the specified hit time in the lateral cooperative guidance law, a distributed coordination strategy is designed to obtain a coordinated hit time, which replaces the specified hit time T. d , the content is as follows: The distributed coordination strategy assumes that each missile can obtain the estimated value of the remaining flight time of the adjacent individuals, and increases the weight of the individuals with longer remaining flight time by weighted average method, so that the coordination time t go,i (t) satisfies the individual hit time range [T min ,T max ], the distributed coordination strategy is: Among them, S i represents the communication topology of cruise missile i; s j represents the number of cruise missiles in its communication topology; k j Represents weight.

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