An attack missile diving section guidance method and system based on a sliding mode control

Abstract

The application discloses a kind of attack bomb dive section guidance method and system based on sliding mode control, it is related to missile guidance and control technical field, first establish the sliding mode guidance law with impact point angle constraint, then using the sliding mode guidance law with impact point angle constraint to control attack bomb, realize attack bomb dive section guidance, by designing the sliding mode guidance law with impact point angle constraint to control attack bomb, it can make up the loss of maneuverability, can obtain greater maneuverability when attack bomb is converted into dive section from horizontal flight section, so as to realize successful guidance, complete the established technical index, satisfy the guidance demand under complex environment.

Description

Technical Field

[0001] This invention relates to the field of missile guidance and control technology, and in particular to a guidance method and system for the dive phase of an offensive missile based on sliding mode control. Background Technology

[0002] With the rapid development of modern combat systems, the complexity of the combat environment is increasing, and the demand for missile offense and defense is also surging. The need for guidance of offensive missiles is growing, which also puts forward new requirements for missile systems.

[0003] Traditional offensive missiles employ a trajectory consisting of a horizontal flight phase followed by a dive attack phase (also known as the dive phase). The horizontal flight phase is more difficult to intercept due to its higher altitude, while the final stage of the dive phase is also challenging due to its high speed. For offensive missiles, the most dangerous interception phase is the transition from the horizontal flight phase to the dive phase. At this point, the flight altitude decreases while the speed does not increase significantly, making it easier to intercept.

[0004] The commonly used guidance method is the conventional proportional guidance method. However, the conventional proportional guidance method results in the missile's limited maneuverability when it transitions from the horizontal flight phase to the dive phase, making it easier to intercept and failing to meet the guidance requirements of complex combat environments. Summary of the Invention

[0005] The purpose of this invention is to provide a guidance method and system for the dive phase of an offensive missile based on sliding mode control, which can compensate for the lack of maneuverability and enable the offensive missile to obtain greater maneuverability when transitioning from the horizontal flight phase to the dive phase, thereby completing guidance and achieving the predetermined technical indicators.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A guidance method for an offensive missile during its dive phase based on sliding mode control, the guidance method for the offensive missile during its dive phase includes:

[0008] Establish a sliding mode guidance law with landing angle constraints;

[0009] The sliding mode guidance law with landing angle constraint is used to control the attack missile and achieve guidance of the attack missile in the dive phase.

[0010] A sliding mode control-based guidance system for an offensive missile during its dive phase, the guidance system comprising:

[0011] The sliding mode guidance law establishment module is used to establish sliding mode guidance laws with landing angle constraints.

[0012] The dive phase guidance control module is used to control the attack missile using the sliding mode guidance law with impact angle constraints, thereby achieving dive phase guidance for the attack missile.

[0013] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0014] This invention provides a sliding mode control-based guidance method and system for the dive phase of an offensive missile. First, a sliding mode guidance law with impact angle constraints is established. Then, the offensive missile is controlled using this sliding mode guidance law to achieve dive phase guidance. By designing a sliding mode guidance law with impact angle constraints to control the offensive missile, the lack of maneuverability can be compensated for. The missile can achieve greater maneuverability when transitioning from the horizontal flight phase to the dive phase, thus ensuring successful guidance, achieving predetermined technical indicators, and meeting guidance requirements in complex environments. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart of the dive-phase guidance method for an offensive missile provided in Embodiment 1 of the present invention;

[0017] Figure 2 This is a flowchart illustrating the implementation of the attack missile dive phase guidance method provided in Embodiment 1 of the present invention.

[0018] Figure 3 This is a comparative schematic diagram of the three-dimensional ballistic trajectory of the offensive projectile provided in Embodiment 1 of the present invention;

[0019] Figure 4 This is a comparative schematic diagram of the height change of the offensive missile provided in Embodiment 1 of the present invention;

[0020] Figure 5 This is a comparative schematic diagram of the maneuverability of the offensive missile provided in Embodiment 1 of the present invention;

[0021] Figure 6 This is a comparative schematic diagram of the trajectory inclination angle of the offensive projectile provided in Embodiment 1 of the present invention;

[0022] Figure 7 This is a schematic diagram of the longitudinal planar ballistic attack and defense confrontation between offensive and interceptor missiles provided in Embodiment 1 of the present invention;

[0023] Figure 8 This is a schematic diagram illustrating the change in the relative distance between the interceptor and the target during ballistic guidance of an offensive missile, as provided in Embodiment 1 of the present invention.

[0024] Figure 9 This is a schematic diagram illustrating the change in the vector miss distance of an interceptor missile during ballistic guidance of an offensive missile, as provided in Embodiment 1 of the present invention.

[0025] Figure 10 This is a schematic diagram illustrating the change in the target-intercept angle between the interceptor and the attacking missile during ballistic guidance of an attacking missile, as provided in Embodiment 1 of the present invention.

[0026] Figure 11 This is a system block diagram of the dive-phase guidance system for an offensive missile provided in Embodiment 2 of the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The purpose of this invention is to provide a guidance method and system for the dive phase of an offensive missile based on sliding mode control. This method can compensate for the lack of maneuverability and enable the offensive missile to have a large maneuverability overload when it transitions from the horizontal flight phase to the dive phase, making it difficult to intercept. This meets the guidance requirements in complex environments, thereby successfully completing the guidance process, achieving the predetermined technical indicators, and solving the practical guidance problems in existing offensive and defensive confrontation scenarios.

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Example 1:

[0031] like Figure 1 and Figure 2 As shown, this embodiment provides a guidance method for the dive phase of an offensive missile based on sliding mode control. The guidance method for the dive phase of the offensive missile includes:

[0032] S1: Establish a sliding mode guidance law with landing angle constraints.

[0033] Specifically, establishing a sliding mode guidance law with landing angle constraints can include:

[0034] (1) Establish the equation of relative motion between the offensive missile and the fixed target.

[0035] This embodiment first establishes the equations of relative motion between the offensive missile and the fixed ground target when the offensive missile strikes the fixed ground target. The specific establishment process is as follows:

[0036] Consider the target location as The position of the attack missile is Then the relative positions of the two are:

[0037] ; (1)

[0038] In equation (1), x rT Let x be the x-component of the relative position of the attack missile and the stationary target; y be the x-component of the relative position of the attack missile and the stationary target. rT The z-axis represents the y-component of the relative position between the attack missile and the stationary target; rT Let x0 be the z-axis component representing the relative position of the attack missile and the stationary target; x0, y0, and z0 are the x, y, and z coordinates of the stationary target's position, respectively; x T y T , z T These are the x, y, and z coordinates of the attack missile's position, respectively.

[0039] It should be noted that the coordinate system used in this embodiment is the line-of-sight coordinate system. The x-axis of the line-of-sight coordinate system is the direction of the line connecting the attack missile and the fixed target, the z-axis is the direction located in the vertical plane containing the x-axis and perpendicular to the x-axis, and the y-axis is established based on the right-hand coordinate system.

[0040] The relative speeds of the two are:

[0041] ; (2)

[0042] In equation (2), The x-component of the relative velocity between the attacking missile and the stationary target. The y-component of the relative velocity between the attack missile and the stationary target. The z-axis component represents the relative velocity between the attack missile and the stationary target. These represent the components of the velocity of a fixed target along the x-axis, y-axis, and z-axis, respectively. These represent the components of the offensive missile's velocity along the x-axis, y-axis, and z-axis, respectively.

[0043] Based on equations (1) and (2), the relative position r between the attack missile and the fixed target in the line-of-sight coordinate system can be calculated. T With relative velocity ,as follows:

[0044] ; (3)

[0045] Simultaneously, the elevation angle of the attack missile's line of sight can be calculated. With respect to the line of sight of the attacking missile ,as follows:

[0046] ; (4)

[0047] By differentiating equation (4), the elevation and angular velocities of the line of sight can be calculated. and line-of-sight azimuth angular velocity ,as follows:

[0048] ; (5)

[0049] In equation (5), The vertical angular velocity is the line-of-sight elevation; x rT Let x be the x-component of the relative position of the attack missile and the stationary target; y be the x-component of the relative position of the attack missile and the stationary target. rT The z-axis represents the y-component of the relative position between the attack missile and the stationary target; rT The z-axis component represents the relative position of the attack missile and the stationary target. The x-component of the relative velocity between the attacking missile and the stationary target. The y-component of the relative velocity between the attack missile and the stationary target. The z-axis component represents the relative velocity between the attack missile and the stationary target. This represents the angular velocity of the line of sight.

[0050] Equation (5) above is the relative motion equation constructed in this embodiment.

[0051] (2) Differentiate the relative motion equation to obtain the differentiated equation; select state variables and transform the differentiated equation into a state-space model. The state variables include line of sight elevation angle, line of sight elevation angular velocity, line of sight azimuth angle and line of sight azimuth angular velocity.

[0052] Taking the derivative of equation (5), the resulting equation is as follows:

[0053] (6)

[0054] In equation (6), The acceleration is the angle of elevation of the line of sight. The relative velocity between the offensive missile and the stationary target; The vertical angular velocity of the line of sight; r T The relative position of the offensive missile and the fixed target; The angular velocity is the line-of-sight azimuth velocity. The elevation angle of the line of sight; a 0sy The initial acceleration component of a fixed target along the y-axis; a Tsy Let y be the component of the initial acceleration of the attack missile along the y-axis. The acceleration is the azimuth angle of the line of sight; a 0sz The initial acceleration component of a fixed target along the z-axis; a Tsz Let be the component of the initial acceleration of the attacking projectile along the z-axis.

[0055] Select state variables , , , Then equation (6) can be rewritten as:

[0056] ; (7)

[0057] Select intermediate parameters as follows:

[0058] (8)

[0059] By transforming equation (7) using the intermediate parameters of equation (8), equation (7) can be rewritten as:

[0060] ; (9)

[0061] In equation (9), x1 is the first state variable. , The elevation angle of the line of sight; x1 is the derivative of the first state variable; x2 is the derivative of the second state variable. , The angular velocity at different elevations of the line of sight; x3 is the derivative of the second state variable; x3 is the third state variable. , This is the azimuth angle of the line of sight; x is the derivative of the third state variable; x4 is the fourth state variable. , The angular velocity is the line-of-sight azimuth velocity. f1 is the derivative of the fourth state variable; f1 is the first intermediate parameter. , Let r be the relative velocity between the attack missile and the stationary target, i.e., the velocity of the attack missile relative to the stationary target. T represents the relative position of the attack missile and the fixed target, i.e., the position of the attack missile relative to the fixed target; g1 is the second intermediate parameter. u1 is the third intermediate parameter. a Tsy d1 represents the initial acceleration component of the attack missile along the y-axis; d1 is the fourth intermediate parameter. a 0sy f1 represents the initial acceleration component of the fixed target along the y-axis; f2 is the fifth intermediate parameter. g2 is the sixth intermediate parameter. u2 is the seventh intermediate parameter. a Tsz d1 represents the initial acceleration component of the attack missile along the z-axis; d2 is the eighth intermediate parameter. a 0sz The initial acceleration component of the fixed target along the z-axis.

[0062] Equation (9) is the state space model constructed in this embodiment, which is also the state equation of the guidance system considering the angle of impact constraint. It can also be called the three-dimensional guidance model of the attack missile in the dive phase or the three-dimensional terminal guidance state space model of the sliding mode.

[0063] (3) Design the sliding surface and the sliding convergence law.

[0064] This embodiment is based on a state-space model and designs a sliding surface and a sliding mode reaching law, specifically as follows:

[0065] Select state variables x1 and x3 as controlled variables, with an expected value of x. 1d With x 3d Define the error e1 = x1 - x 1d The derivative of the error , The second derivative of the error .

[0066] The linear sliding surface is designed as follows:

[0067] ; (10)

[0068] In equation (10), s1 is the sliding surface; c1 is the coefficient of the sliding surface; e1 is the error, e1=x1-x 1d x1 is the first state variable. , x is the elevation angle of the line of sight. 1d This represents the expected value of the elevation angle of the line of sight; This is the derivative of the error.

[0069] Differentiating equation (10), we get:

[0070] ; (11)

[0071] Choosing the exponential reaching law as the reaching law, the sliding mode reaching law is designed as follows:

[0072] ;(12)

[0073] In equation (12), Here, k1 is the first coefficient of the sliding mode convergence law. This is the second coefficient of the sliding mode reaching law.

[0074] (4) Based on the state space model, sliding surface and sliding mode approach law, establish a sliding mode guidance law with landing angle constraint.

[0075] Based on the designed sliding mode surface and sliding mode approach law, this embodiment provides a sliding mode control law and a longitudinal acceleration command for the attack projectile. Furthermore, a sliding mode guidance law with impact angle constraints is designed. The specific process is as follows:

[0076] make By combining equations (9) and (11), the equivalent control law can be obtained as follows:

[0077] ; (13)

[0078] Substituting the exponential approach law shown in equation (12) into equation (13), we can obtain the sliding mode control law as follows:

[0079] ;(14)

[0080] By combining equations (8) and (14), the acceleration command a of the longitudinal plane attack missile can be obtained. Ty for:

[0081] (15)

[0082] In this embodiment, the proportional guidance law is still used in the lateral plane, so the acceleration command a of the lateral plane attack missile is... Tz for:

[0083] ; (16)

[0084] In equation (16), N is the proportional guidance coefficient; This represents the rate of change of the relative distance between the attack missile and the fixed target.

[0085] Therefore, the sliding mode guidance law with landing angle constraint is obtained as follows:

[0086] (17)

[0087] In equation (17), a Ty This refers to the y-component of the acceleration command, which is also the longitudinal guidance command for the attack missile; r T c1 represents the relative position of the attack missile and the stationary target; c1 is the coefficient of the sliding surface. The angular velocity at different elevations of the line of sight; The relative velocity between the offensive missile and the stationary target; θ is the angular velocity of the line of sight; k1 is the first coefficient of the sliding mode approach law; s1 is the sliding surface; a is the second coefficient of the sliding mode reaching law; Tz The acceleration command is the component on the z-axis, which is also the lateral guidance command for the attack missile; N is the proportional guidance coefficient. This represents the rate of change of the relative distance between the attack missile and the fixed target.

[0088] In this embodiment, the landing angle constraint of the sliding mode guidance law with landing angle constraint refers to the expected value x of the line-of-sight elevation angle. 1d constraint.

[0089] S2: The sliding mode guidance law with landing angle constraint is used to control the attack missile and achieve guidance of the attack missile in the dive phase.

[0090] After constructing the sliding mode guidance law with impact angle constraint as shown in equation (17), the real-time position of the attacking missile can be substituted into equation (17) to calculate a. Ty and a Tz This process controls the attack missile and calculates its real-time position at the next moment. The missile's position is calculated using its dynamic equations.

[0091] The dynamic equations of the offensive missile are as follows:

[0092] (18)

[0093] In equation (18), m T For the mass of the offensive missile; V T For the velocity of the attacking projectile; X T g represents the drag of an offensive projectile. T This represents the magnitude of gravitational acceleration. For the trajectory inclination of the offensive missile; Y T The magnitude of the offensive lift force; Z represents the tilt angle of the attack missile. T This refers to the magnitude of the lateral force of the attack missile; For the trajectory deflection of an offensive missile; x T y T , z T This indicates the position of the attack missile.

[0094] This embodiment provides a sliding mode control-based guidance method for an offensive missile during its dive phase. The method includes: establishing a state-space model of the offensive missile; designing a sliding mode surface and a sliding mode approach law to provide the missile's sliding mode control law and longitudinal and lateral overload commands; establishing a sliding mode guidance law with impact angle constraints; and subsequently using this law to control the missile and complete the guidance process. This method can enable the offensive missile to have significant maneuver overload capability during the dive phase, completing the guidance process and achieving predetermined technical targets. It has significant performance advantages and broad application prospects.

[0095] To compare the sliding mode guidance law with impact angle constraints proposed in this embodiment, this embodiment provides an acceleration command for an attack missile under proportional guidance, that is, establishing a proportional guidance law with impact angle constraints used in conventional proportional guidance methods for simulation comparison. Specifically, the attack missile dive phase guidance method of this embodiment also includes performance evaluation of the sliding mode guidance law with impact angle constraints, which may include: establishing a proportional guidance law with impact angle constraints; controlling the attack missile based on the proportional guidance law with impact angle constraints to determine the first trajectory and first overload of the attack missile; controlling the attack missile based on the sliding mode guidance law with impact angle constraints to determine the second trajectory and second overload of the attack missile; comparing the first trajectory and the second trajectory to obtain a first comparison result; comparing the first overload and the second overload to obtain a second comparison result; and combining the first comparison result and the second comparison result to evaluate the performance of the sliding mode guidance law with impact angle constraints.

[0096] The establishment process of the proportional guidance law with landing angle constraints is as follows:

[0097] The pitch channel uses a proportional guidance law, as follows:

[0098] (19)

[0099] Equation (19) above is the overload command for the elevation channel of the attack missile. In equation (19), V T For the velocity of the attacking projectile; t go The remaining flight time is for proportional guidance; N is the proportional guidance coefficient. The elevation angle of the line of sight for offensive missiles; The trajectory inclination angle; The desired landing angle.

[0100] The yaw channel uses a proportional guidance law, as follows:

[0101] ; (20)

[0102] Equation (20) above is the overload command for the yaw path of the attack missile. In equation (20), The rate of change of the relative distance between the projectile and the target; This represents the angular velocity of the line of sight.

[0103] Therefore, the proportional guidance law with landing angle constraint is obtained as follows:

[0104] ;(twenty one)

[0105] A ballistic trajectory refers to the path formed by an attacking missile during the control process, including its position at various moments. The process of determining the first trajectory includes: controlling the attacking missile based on a proportional guidance law with impact angle constraints, and calculating the position of the attacking missile at various moments using the dynamic equation shown in equation (18) to obtain the first trajectory. The process of determining the second trajectory includes: controlling the attacking missile based on a sliding mode guidance law with impact angle constraints, and calculating the position of the attacking missile at various moments using the dynamic equation shown in equation (18) to obtain the second trajectory. The first overload and the second overload can be obtained during the control process of the attacking missile.

[0106] This embodiment can also establish a relative motion model (also known as relative motion equation) for offensive and defensive confrontation between offensive and interceptor missiles based on acceleration commands under sliding mode guidance and proportional guidance laws, conduct offensive and defensive confrontation, i.e., perform interception simulation, and calculate the final miss distance of the interceptor missile to evaluate the performance of the sliding mode guidance law and obtain the guidance effect in the dive phase. Specifically, the dive phase guidance method of the offensive missile in this embodiment also includes evaluating the performance of the sliding mode guidance law with impact angle constraints, which may include: establishing the proportional guidance law of the interceptor missile when intercepting the offensive missile; calculating the miss distance based on the sliding mode guidance law and proportional guidance law with impact angle constraints; and evaluating the performance of the sliding mode guidance law with impact angle constraints based on the miss distance.

[0107] The process of establishing the proportional guidance law for interceptor missiles is as follows:

[0108] Considering the position of the interceptor missile is Then the relative positions of the offensive missile and the interceptor missile are:

[0109] ; (twenty two)

[0110] The relative speed is:

[0111] ; (twenty three)

[0112] The relative positions r of the attack missile and the interceptor missile in the line-of-sight coordinate system can then be calculated. M With relative velocity for:

[0113] ; (twenty four)

[0114] Simultaneously, the elevation angle of the interceptor missile's line of sight can be calculated. With the line of sight of the interceptor missile for:

[0115] ; (25)

[0116] By differentiating equation (25), the elevation angular velocity of the interceptor missile can be calculated. angular velocity of the interceptor missile's line of sight azimuth for:

[0117] ; (26)

[0118] Equation (26) above is the equation of relative motion between the attack missile and the interceptor missile.

[0119] The three-dimensional proportional guidance law designed for the terminal guidance phase of an interceptor missile intercepting an offensive missile is as follows:

[0120] ;(27)

[0121] Equation (27) above is the proportional guidance law for interceptor missiles. In equation (27), a My For the longitudinal guidance command of the interceptor missile, a Mz This is a lateral guidance command for the interceptor missile.

[0122] The formula for calculating the miss distance of an interceptor missile is:

[0123] ; (28)

[0124] In equation (28), R is the miss distance; For the velocity vector of the attacking projectile; The velocity vector of the interceptor missile; This is the position vector of the attack missile; This is the position vector of the interceptor missile.

[0125] The scalar form of each vector is as follows:

[0126] ; (29)

[0127] The specific expression is as follows:

[0128] ; (30)

[0129] In equation (30), v T0x v is the initial velocity of the attack missile in the x-direction; t is the flight time of the attack missile; T0y v represents the initial y-velocity of the attack missile. T0z Let a be the initial velocity of the attacking missile in the z-direction. Ty a Tz Determined based on the sliding mode guidance law with landing angle constraints.

[0130] ; (31)

[0131] In equation (31), v M0xv represents the initial velocity of the interceptor missile in the x-direction. M0y v represents the initial y-velocity of the interceptor missile. M0z Let a be the initial z-direction velocity of the interceptor missile. My a Mz Determined based on the proportional guidance law of the interceptor missile.

[0132] ; (32)

[0133] In equation (32), r T0x The initial x-direction position of the attack missile; r T0y The initial y-direction position of the attack missile; r T0z This represents the initial z-direction position of the attack missile.

[0134] ; (33)

[0135] In equation (33), r M0x r represents the initial x-direction position of the interceptor missile. M0y r represents the initial y-position of the interceptor missile. M0z This represents the initial z-direction position of the interceptor missile.

[0136] The following simulation, using Matlab and Visual Studio, illustrates the fixed-altitude guidance process of an attack missile striking a surface target while an interceptor missile is launched vertically from the sea.

[0137] The simulation parameters are set as follows:

[0138] The parameters of the attack missile are: initial altitude 30km, initial velocity 7Ma (Mach number), initial trajectory inclination 0°, lateral distance of 70km in the dive phase, and landing angle of -75°.

[0139] The interceptor parameters are as follows: the interception point altitude is selected as 20km, the initial launch trajectory inclination angle is 90°, the maximum flight altitude is 30km, and the engine burn time is 46s.

[0140] The parameters of the sliding mode controller are: .

[0141] The three-dimensional ballistic trajectory comparison diagram and altitude change comparison diagram of the offensive missile using sliding mode guidance (i.e., the method of this embodiment) and proportional guidance (i.e., the conventional proportional guidance method) are shown below. Figure 3 and Figure 4 As shown, Figure 3 In this context, H refers to the y-coordinate. From... Figure 3 and Figure 4It can be seen that the trajectory of a sliding mode guided ballistic missile is at a relatively high altitude at the beginning of the dive phase. If interception occurs at this time, the interceptor missile will be at too high an altitude when it approaches the target, and the atmospheric density will be reduced. As a result, the interceptor missile will not have enough aerodynamic control force and will eventually miss the target. At the same time, the trajectory of a sliding mode guided ballistic missile is more curved, which increases the difficulty of interception. Figure 5 The diagram shows the overload variation of the attack missile. During the initial sliding mode guidance phase of the dive, the overload is much greater than that of the proportional guidance, thus giving it strong maneuverability and making it difficult to intercept. Figure 6 The diagram shows a comparison of the landing angles. Both proportional guidance and sliding mode guidance satisfy the -75° landing angle constraint.

[0142] The diagram shows the changes in the interceptor missile. Figures 7 to 10 , Figure 7 The longitudinal plane trajectory diagrams of the attack and intercept trajectories in the interceptor coordinate system show that the interceptor trajectory tends to flatten as it approaches the target point, resulting in the angle between the velocity directions of the interceptor and the attacking missile being less than 180°, which is a side attack situation. Compared with the situation of attacking head-on with parallel velocity directions, the miss distance is greater. Figure 8 This is a graph showing the change in the relative distance between the projectile and the target. Figure 9 The graph shows the change in the magnitude of the vector miss distance. At the final moment, the miss distance is 5.322m, which is greater than the kill zone radius of the interceptor missile (5m). Therefore, the attack missile was successfully guided. Figure 10 The diagram shows the change in the missile-target encounter angle, indicating that the interceptor missile was launched vertically. When it approached the target, the missile-target encounter angle was 132°, which is a side attack situation, resulting in a larger miss distance.

[0143] This embodiment discloses a sliding mode control-based guidance method for the dive phase of an offensive missile, solving the problem that existing proportional guidance methods for offensive missiles are easily intercepted during the dive phase. The method includes the following steps: establishing the relative motion equations of the offensive missile striking a fixed target; constructing the state equations of the guidance system considering the angle of impact constraint; designing the sliding mode surface and sliding mode approach law; providing the sliding mode control law and the longitudinal acceleration command of the offensive missile; establishing the sliding mode guidance law with the impact angle constraint; providing the acceleration command of the offensive missile under proportional guidance for simulation comparison; establishing the relative motion equations of the offensive missile and the interceptor missile; conducting offensive and defensive countermeasures; calculating the final miss distance of the interceptor missile; and obtaining the dive phase guidance effect of the offensive missile dive phase guidance method of this embodiment. Using the offensive missile dive phase guidance method of this embodiment, the offensive missile has greater maneuverability and a higher altitude during the dive phase, making it difficult for the interceptor missile to intercept successfully.

[0144] Example 2:

[0145] This embodiment provides a sliding mode control-based guidance system for an offensive missile during its dive phase, such as... Figure 11 As shown, the dive-phase guidance system of the offensive missile includes:

[0146] The sliding mode guidance law establishment module M1 is used to establish a sliding mode guidance law with landing angle constraints.

[0147] The dive phase guidance control module M2 is used to control the attack missile using the sliding mode guidance law with landing angle constraints, so as to achieve dive phase guidance of the attack missile.

[0148] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0149] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A guidance method for the dive phase of an offensive missile based on sliding mode control, characterized in that, include: Establish a sliding mode guidance law with landing angle constraints; The sliding mode guidance law with impact angle constraint is used to control the attack missile and achieve guidance of the attack missile in the dive phase. The establishment of the sliding mode guidance law with landing angle constraints specifically includes: Establish the equations of relative motion between the offensive missile and the fixed target; The relative motion equation is differentiated to obtain the differentiated equation; state variables are selected, and the differentiated equation is transformed into a state-space model; the state variables include line of sight elevation angle, line of sight elevation angular velocity, line of sight azimuth angle, and line of sight azimuth angular velocity. Design sliding surfaces and sliding mode convergence laws; Based on the state space model, the sliding surface, and the sliding mode reaching law, a sliding mode guiding law with landing angle constraints is established. The sliding surface is: ； in, s 1 represents the sliding surface; c 1 represents the coefficient of the sliding surface; e 1 represents the error. e 1= x 1- x 1d , x 1 is the first state variable. , For the elevation angle of the line of sight, x 1d This represents the expected value of the elevation angle of the line of sight; The derivative of the error; The sliding mode reaching law is: ； in, This is the sliding mode approach law; k 1 is the first coefficient of the sliding mode reaching law; This is the second coefficient of the sliding mode reaching law; The sliding mode guidance law with landing angle constraint is as follows: ； in, a Ty For acceleration commands in y The components of the axis; r T The relative position of the offensive missile and the fixed target; c 1 represents the coefficient of the sliding surface; The angular velocity at different elevations of the line of sight; The relative velocity between the offensive missile and the stationary target; The angular velocity is the line-of-sight azimuth velocity. The elevation angle of the line of sight; k 1 is the first coefficient of the sliding mode reaching law; s 1 represents the sliding surface; This is the second coefficient of the sliding mode reaching law; a Tz For acceleration commands in z The components of the axis; N This is the proportional guidance coefficient; This represents the rate of change of the relative distance between the attack missile and the fixed target.

2. The method for guiding an offensive missile in the dive phase based on sliding mode control according to claim 1, characterized in that, The equation of relative motion is: ； in, The angular velocity at different elevations of the line of sight; x rT The relative position of the offensive missile and the fixed target in x The components of the axis; y rT The relative position of the offensive missile and the fixed target in y The components of the axis; z rT The relative position of the offensive missile and the fixed target in z The components of the axis; For the relative velocity between the offensive missile and the stationary target x The components of the axis; For the relative velocity between the offensive missile and the stationary target y The components of the axis; For the relative velocity between the offensive missile and the stationary target z The components of the axis; This represents the angular velocity of the line of sight.

3. The method for guiding an offensive missile during its dive phase based on sliding mode control according to claim 1, characterized in that, The state-space model is as follows: ； in, x 1 is the first state variable. , The elevation angle of the line of sight; The derivative of the first state variable; x 2 is the second state variable. , The angular velocity at different elevations of the line of sight; The derivative of the second state quantity; x 3 is the third state variable. , This is the azimuth angle of the line of sight; The derivative of the third state quantity; x 4 is the fourth state variable. , The angular velocity is the line-of-sight azimuth velocity. The derivative of the fourth state quantity; f 1 is the first intermediate parameter. , The relative velocity between the attack missile and the stationary target. r T The relative position of the offensive missile and the fixed target; g 1 is the second intermediate parameter. ; u 1 is the third intermediate parameter. , a Tsy The initial acceleration of the attacking missile at y The components of the axis; d 1 is the fourth intermediate parameter. , a 0sy The initial acceleration of a fixed target in y The components of the axis; f 2 is the fifth intermediate parameter. ; g 2 is the sixth intermediate parameter. ; u 2 is the seventh intermediate parameter. , a Tsz For the initial acceleration of the attacking missile at z The components of the axis; d 2 is the eighth intermediate parameter. , a 0sz The initial acceleration of a fixed target in z The components of the axis.

4. The method for guiding an offensive missile in the dive phase based on sliding mode control according to claim 2, characterized in that, The position of the attack missile is calculated using the missile's dynamic equations.

5. The method for guiding an offensive missile in the dive phase based on sliding mode control according to claim 1, characterized in that, It also includes: performance evaluation of the sliding mode guidance law with landing angle constraints, specifically including: A proportional guidance law with impact angle constraint is established, and the attack missile is controlled based on the proportional guidance law with impact angle constraint to determine the first trajectory and first overload of the attack missile. The attack missile is controlled based on the sliding mode guidance law with impact angle constraint to determine the second trajectory and second overload of the attack missile. By comparing the first trajectory and the second trajectory, a first comparison result is obtained; Compare the first overload and the second overload to obtain a second comparison result; The performance of the sliding mode guidance law with landing angle constraint is evaluated by combining the first comparison result and the second comparison result.

6. The method for guiding an offensive missile in the dive phase based on sliding mode control according to claim 1, characterized in that, It also includes: performance evaluation of the sliding mode guidance law with landing angle constraints, specifically including: Establish a proportional guidance law for interceptor missiles when intercepting offensive missiles; The miss distance is calculated based on the sliding mode guidance law with the landing angle constraint and the proportional guidance law, and the performance of the sliding mode guidance law with the landing angle constraint is evaluated based on the miss distance.

7. A sliding mode control-based guidance system for an offensive missile during its dive phase, operating based on the sliding mode control-based guidance method for an offensive missile during its dive phase as described in claim 1, characterized in that... include: The sliding mode guidance law establishment module is used to establish sliding mode guidance laws with landing angle constraints. The dive phase guidance control module is used to control the attack missile using the sliding mode guidance law with impact angle constraints, thereby achieving dive phase guidance for the attack missile.

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