Control method for interceptor under attitude and orbit combination

Abstract

The invention discloses a control method of an attitude-orbit composite lower interceptor, and relates to the technical field of automatic control. Obtaining a strong coupling state space equation according to an angular acceleration calculation formula of the sight angle and a kinetic equation of the interceptor; constructing a high-order multi-dimensional sliding mode matrix according to the strong coupling state space equation, and designing a strong coupling control law of an attitude control engine and an orbit control engine of the interceptor according to the high-order multi-dimensional sliding mode matrix; according to a stable condition and a fixed time convergence condition of an interceptor guidance control system under attitude and orbit combination, solving an interference term in the strong coupling control law to obtain an estimated value of the interference term; and substituting the estimated value of the interference item and the state data of the interceptor into a strong coupling control law of the interceptor to obtain lateral thrust which is generated by an attitude control engine and an orbit control engine and is vertical to a projectile body shaft so as to control the interceptor. The method can improve the control precision of the interceptor.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic control, and particularly relates to a control method for an interceptor under combined attitude and trajectory control. Background Art

[0002] Currently, a combined attitude and trajectory control system consists of trajectory control engines installed near the centroid of the interceptor and attitude control engines installed at a relatively long distance in front of or behind the centroid, which can provide lateral thrust and torque for the interceptor to change the acceleration and attitude of the interceptor.

[0003] However, in practical applications, the combined attitude and trajectory control system has the following characteristics: (1) the direction of the direct lateral force is fixed to the missile body and perpendicular to the missile body axis, changing with the attitude of the interceptor; (2) the attitude control engine generates force and torque increments simultaneously; (3) due to fuel consumption and installation errors, the deviation between the thrust action point of the trajectory control engine and the centroid is inevitable, resulting in the trajectory control engine also generating force and torque increments simultaneously. The above characteristics lead to serious control input coupling and trajectory / attitude coupling problems in the guidance and control system of the interceptor under combined attitude and trajectory control.

[0004] However, in the prior art, there is a problem of low control accuracy in the control of the interceptor under combined attitude and trajectory control. Summary of the Invention

[0005] Based on this, it is necessary to provide a control method for an interceptor under combined attitude and trajectory control to solve the above technical problems, which can improve the control accuracy of the interceptor.

[0006] The present invention adopts the following technical solutions: The present invention provides a control method for an interceptor under combined attitude and trajectory control, including: Determining a calculation formula for the angular acceleration of the line-of-sight angle between the interceptor and the target according to the relative kinematic equation of the interceptor and the target in the longitudinal plane; Constructing a strongly coupled state-space equation according to the calculation formula for the angular acceleration of the line-of-sight angle and the dynamic equation of the interceptor; Constructing a high-order multi-dimensional sliding mode matrix according to the strongly coupled state-space equation, and designing a strongly coupled control law for the attitude control engine and the trajectory control engine of the interceptor according to the high-order multi-dimensional sliding mode matrix; the high-order multi-dimensional sliding mode matrix satisfies the field-of-view constraint of the strapdown seeker of the interceptor; Solving the disturbance term in the strongly coupled control law according to the stability condition and the fixed-time convergence condition of the guidance and control system of the interceptor under combined attitude and trajectory control to obtain an estimated value of the disturbance term; Substituting the estimated value of the disturbance term and the state data of the interceptor into the strongly coupled control law of the interceptor to obtain the lateral thrust perpendicular to the missile body axis generated by the attitude control engine and the trajectory control engine; The interceptor is controlled by the lateral thrusts generated by the attitude control engines and the trajectory control engines, which are perpendicular to the missile body axis.

[0007] Optionally, according to the relative kinematic equation of the interceptor and the target in the longitudinal plane, the calculation formula for the angular acceleration of the line-of-sight angle between the interceptor and the target is determined, including: Substitute the calculation formula for the ballistic inclination angle rate of the interceptor into the relative kinematic equation of the interceptor and the target in the longitudinal plane to obtain the calculation formula for the angular acceleration of the line-of-sight angle; The relative kinematic equation of the interceptor and the target in the longitudinal plane is: ; Wherein, and respectively represent the relative distance of the projectile and the line-of-sight angle, represents the first-order derivative with respect to time, represents the first-order derivative with respect to time, and respectively represent the ballistic inclination angles of the interceptor and the target, and respectively represent the speeds of the interceptor and the target; The calculation formula for the ballistic inclination angle rate of the interceptor is: ; Wherein, represents the ballistic inclination angle rate of the interceptor, which is the first-order derivative of , represents the interceptor velocity vector, and respectively represent the lateral thrusts generated by the attitude control engines and the trajectory control engines, which are perpendicular to the missile body axis, represents the angle of attack, represents the lift force generated by aerodynamic force, represents the mass of the interceptor; The calculation formula for the angular acceleration of the line-of-sight angle: ; Wherein, represents the angular acceleration of the line-of-sight angle, represents the first interference parameter, represents the acceleration due to gravity, represents the acceleration of the target.

[0008] Optionally, the dynamic equation of the interceptor is: ; Wherein, represents the body line-of-sight angle of the interceptor, represents the first derivative of represents the pitch angle rate of the interceptor, represents the second interference parameter, represents the third interference parameter, represents the first derivative with respect to time, represents the dynamic pressure, represents the maximum cross-sectional area of the interceptor, represents the length of the interceptor, and respectively represent with respect to and the pitch moment coefficients, and respectively represent the distances from the action points of the attitude control engine and the orbit control engine thrust to the warhead, represents the distance from the center of mass to the warhead, represents the moment of inertia of the interceptor about the z-axis of the body coordinate system.

[0009] Optionally, according to the angular acceleration calculation formula of the line of sight angle and the dynamic equation of the interceptor, a strongly coupled state space equation is constructed, including: Based on the angular acceleration calculation formula of the line of sight angle and the dynamic equation of the interceptor, define , , , and , and determine the strongly coupled state space equation as: ; where represents the first derivative of represents the first derivative of represents the first derivative of , , , , , , , , , , , , , , and represent interference terms.

[0010] Optionally, according to the high-order multi-dimensional sliding mode matrix, design the strong coupling control law for the attitude control engine and the orbit control engine of the interceptor, including: According to the high-order multi-dimensional sliding mode matrix, design the reaching law; Substitute the high-order multi-dimensional sliding mode matrix into the reaching law to obtain the strong coupling control law for the attitude control engine and the orbit control engine of the interceptor; High-order multi-dimensional sliding mode matrix is: ; Reaching law is: ; where and respectively represent the estimated value and the estimation error of , ; , , , , , and are all positive constants; The strong coupling control law for the attitude control engine and the orbit control engine of the interceptor is: ; where , , , , .

[0011] Optionally, according to the stability condition and the fixed-time convergence condition of the interceptor guidance and control system under the attitude-orbit compound, solve the interference term in the strong coupling control law to obtain the estimated value of the interference term, including: According to the stability condition and the fixed-time convergence condition, determine the constraint condition of the learning rate in the neural network model; Train the neural network model according to the constraint condition of the learning rate in the neural network model; Input the relative distance between the interceptor and the target, the line-of-sight angle rate of the interceptor, the body line-of-sight angle, and the pitch angle rate into the trained neural network model to obtain the estimated value of the interference term.

[0012] Optionally, according to the stability condition and the fixed-time convergence condition, determine the constraint condition of the learning rate in the neural network model, including: According to the stability condition, determine the first constraint condition of the learning rate in the neural network model; Determine the second constraint condition of the learning rate in the neural network model according to the fixed-time convergence condition; Determine the constraint condition of the learning rate in the neural network model according to the first constraint condition and the second constraint condition.

[0013] Optionally, determine the first constraint condition of the learning rate in the neural network model according to the stability condition, including: Design a Lyapunov function according to the stability condition; Calculate the first-order derivative of the Lyapunov function with respect to time; Determine the first constraint condition under the condition that the first-order derivative of the Lyapunov function with respect to time satisfies less than or equal to 0.

[0014] Optionally, determine the second constraint condition of the learning rate in the neural network model according to the fixed-time convergence condition, including: Calculate the derivative of the cost function in the neural network model with respect to time; Determine the second constraint condition under the condition that the derivative of the cost function in the neural network model with respect to time satisfies the fixed-time convergence condition.

[0015] Optionally, the first constraint condition is: , , ; The second constraint condition is: ; The constraint condition of the learning rate is: ; Among them, the interference term in the strong coupling control law includes the first interference term , the second interference term and the third interference term , represents the learning rate corresponding to the first interference term , represents the learning rate corresponding to the second interference term , represents the learning rate corresponding to the third interference term , , , are all positive constants, , and are both greater than 0, , represents the output of the th neuron in the hidden layer of the neural network.

[0016] The present invention provides a control device for an interceptor under attitude-orbit compounding, including: A determination module, configured to determine a calculation formula for the angular acceleration of the line-of-sight angle between the interceptor and the target according to the relative kinematic equation of the interceptor and the target in the longitudinal plane; A custom module, configured to construct a strongly coupled state-space equation according to the calculation formula for the angular acceleration of the line-of-sight angle and the dynamic equation of the interceptor; A design module, configured to construct a high-order multi-dimensional sliding mode matrix according to the strongly coupled state-space equation, and design a strongly coupled control law for the interceptor according to the high-order multi-dimensional sliding mode matrix; the high-order multi-dimensional sliding mode matrix satisfies the field-of-view constraint of the strapdown seeker of the interceptor; A solution module, configured to solve the interference term in the strongly coupled control law according to the stability condition and the fixed-time convergence condition of the interceptor guidance and control system under the combined attitude and trajectory, and obtain an estimated value of the interference term; An obtaining module, configured to substitute the estimated value of the interference term and the state data of the interceptor into the strongly coupled control law of the interceptor to obtain the lateral thrusts generated by the attitude control engine and the trajectory control engine perpendicular to the missile body axis; A control module, configured to control the interceptor by means of the lateral thrusts generated by the attitude control engine and the trajectory control engine perpendicular to the missile body axis.

[0017] The present invention provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the control method of the interceptor under the combined attitude and trajectory as described above is implemented.

[0018] The present invention provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the program, the control method of the interceptor under the combined attitude and trajectory as described above is implemented.

[0019] The above at least one technical solution adopted by the present invention can achieve the following beneficial effects: By constructing a high-order multi-dimensional sliding mode matrix and designing a strongly coupled control law for the attitude control engine and the trajectory control engine of the interceptor, the efficient utilization and compensation of the coupling effect between the attitude control engine and the trajectory control engine are realized; combined with the stability condition and the fixed-time convergence condition of the interceptor guidance and control system under the combined attitude and trajectory, the interference term in the strongly coupled control law is solved to obtain an estimated value of the interference term, and the fixed-time convergence of the approximation error is realized on the premise of taking into account the stability of the control system, thereby improving the control accuracy of the interceptor under complex interference. Description of the Drawings

[0020] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute an improper limitation to the present invention. In the drawings:

[0021] Figure 1 Schematic diagram of the control method process of an interceptor under combined attitude and trajectory control provided by the present invention; Figure 2 Schematic diagram of the combined attitude and trajectory control effect in the initial state and the interception process; Figure 3 Schematic diagram of the response curve of the body line-of-sight angle changing with time under different degrees of centroid drift of SCC and GC; Figure 4 Schematic diagram of the response curve of the pitch angle rate changing with time under different degrees of centroid drift of SCC and GC; Figure 5 Schematic diagram of the state response curve under FTRBFNN and RBFNN provided by the present invention; Figure 6 Schematic diagram of the miss distance result of the Monte Carlo shooting of the control method of an interceptor under combined attitude and trajectory control provided by the present invention; Figure 7 Schematic diagram of the control device of an interceptor under combined attitude and trajectory control provided by the present invention; Figure 8 Schematic diagram of a computer device for implementing the control method of an interceptor under combined attitude and trajectory control provided by the present invention. Detailed implementation manners

[0022] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0023] Near-space vehicles generally have characteristics such as high flight speed, strong maneuverability, and the need for kinetic energy kill, which pose extremely high requirements for the guidance and control accuracy and response speed of interceptors.

[0024] During the flight of a near-space target interceptor, it is affected by static and time-varying factors and faces the strong uncertainty challenges caused by multi-source interference. On the one hand, as the flight altitude increases, the spatial atmospheric density, temperature, and dynamic pressure change significantly, thus forming unpredictable high-temperature gas effects, rarefied gas effects, and flow transition phenomena, which cause the uncertainty of the pressure distribution on the missile body surface and lead to drastic changes in the aerodynamic moments acting on the interceptor. On the other hand, factors such as the attitude-orbit composite control manipulation error, combined coordination error, and the time-varying mass characteristics caused by fuel consumption bring great internal uncertainties to the guidance and control. Traditional interference identification techniques are proposed for individual interference sources. When facing multi-source interference, the strategy of independent identification of each interference is often adopted, and the identification speeds of each interference lack consistency, which is not conducive to the unified regulation of the control system accuracy and convergence speed.

[0025] With the development of computing technology, for the problem of uncertainty identification and control of low-precision models, researchers have proposed data-driven intelligent control methods, such as neural networks, fuzzy logic systems, support vector machines, and Gaussian process regression. Neural networks are widely used to construct interference observers because they can approximate nonlinear functions with arbitrary precision, have low dependence on models, and have strong adaptive capabilities. In particular, radial basis neural networks are widely used in the research of aircraft control due to their simple network structure and low computational pressure. However, the existing theoretical research on the stability, convergence, etc. of neural network control systems is not yet perfect, and it greatly depends on the experience of designers in related parameter settings.

[0026] However, the control methods of interceptors in the existing technology have the following defects: (1) For the guidance and control system under strong coupling, there is a lack of integrated research on guidance and control that integrates the complex coupling effects of attitude-orbit composite control; (2) There is a lack of theoretical research on the approximation performance of neural network interference observers, and it is impossible to flexibly control the approximation time of the neural network to interference.

[0027] Based on this, the present invention provides a control method for an interceptor under attitude-orbit composite control for the problem of high-speed target interception under attitude-orbit composite control, which utilizes beneficial coupling and compensates for adverse coupling; at the same time, combined with a fixed-time neural network interference observer, it realizes the synchronous estimation and compensation of multi-source mismatched interference, and improves the overall performance of the guidance and control system of the interceptor.

[0028] The following will describe in detail the technical solutions provided by each embodiment of the present invention with reference to the accompanying drawings.

[0029] Figure 1 It is a schematic flow diagram of a control method for an interceptor under attitude-orbit composite in the present invention, which specifically includes the following steps: S101, according to the relative kinematic equation of the interceptor and the target in the longitudinal plane, determine the angular acceleration calculation formula of the line-of-sight angle between the interceptor and the target.

[0030] Ideally, the effects of attitude control and trajectory control are independent of each other. However, in reality, attitude / trajectory control is severely coupled, and the coupling interference intensifies with the increase of the centroid drift. The combined attitude and trajectory control effects in the initial state and during the interception process are as follows Figure 2 shown as Figure 2 Figure (a) in Figure 2 shows the schematic diagram of the combined attitude and trajectory control effect in the initial state. Among them, and respectively represent the lateral thrusts perpendicular to the missile body axis generated by the attitude control engine and the trajectory control engine. and respectively represent the distances from the action points of the thrusts of the attitude control engine and the trajectory control engine to the warhead. represents the distance from the centroid to the warhead. represents the centroid drift distance caused by fuel consumption during the flight process. represents the missile body axis. represents the angle of attack. represents the interceptor velocity vector.

[0031] The forces and moments acting on the interceptor under combined attitude and trajectory control can be written in the following form: (1); where and are respectively the sum of the force increment and the moment increment of the interceptor. and respectively represent the lift force and the pitching moment generated by aerodynamic forces. represents the centroid drift distance. For the sake of convenient writing, in the following text, and will be respectively abbreviated as and .

[0032] The relative kinematic equations of the interceptor and the target in the longitudinal plane are: (2); where and respectively represent the relative distance of the projectile and the line-of-sight angle. represents the first derivative with respect to time. represents the first derivative with respect to time. and respectively represent the ballistic inclinations of the interceptor and the target. and respectively represent the speeds of the interceptor and the target.

[0033] The calculation formula for the ballistic inclination angle velocity of the interceptor is as follows: (3); Wherein, represents the ballistic inclination angle velocity of the interceptor, and is the first derivative of , represents the velocity vector of the interceptor, and respectively represent the lateral thrusts perpendicular to the missile body axis generated by the attitude control engine and the trajectory control engine, represents the angle of attack, represents the lift force generated by aerodynamic force, represents the mass of the interceptor.

[0034] Therefore, according to the relative kinematic equation of the interceptor and the target in the longitudinal plane, the calculation formula for the angular acceleration of the line-of-sight angle between the interceptor and the target is determined, including: substituting the calculation formula for the ballistic inclination angle velocity of the interceptor into the relative kinematic equation of the interceptor and the target in the longitudinal plane to obtain the calculation formula for the angular acceleration of the line-of-sight angle. That is, substituting formula (3) into formula (2), the calculation formula for the angular acceleration of the line-of-sight angle can be obtained:

[0035] (4); Wherein, represents the angular acceleration of the line-of-sight angle, represents the first interference parameter, represents the gravitational acceleration, represents the acceleration of the target.

[0036] S102. Construct a strongly coupled state space equation according to the calculation formula for the angular acceleration of the line-of-sight angle and the dynamic equation of the interceptor.

[0037] The strapdown seeker is widely used in precision guidance interceptors due to its small size, light weight, low cost, high reliability, and insensitivity to missile body overload. The field of view of the strapdown seeker is fixedly connected to the missile body, and its measured information is the body line-of-sight angle , and in the longitudinal plane, there is , where , and respectively represent the pitch angle and pitch angle rate of the interceptor. On this basis, the dynamic equation of the interceptor is:

[0038] (5); Wherein, represents the body line-of-sight angle of the interceptor, represents the first derivative of, represents the pitch angle rate of the interceptor, represents the second interference parameter, represents the third interference parameter, represents the first-order derivative with respect to time, represents the dynamic pressure, represents the maximum cross-sectional area of the interceptor, represents the length of the interceptor, and respectively represent the pitch moment coefficients with respect to and ; and respectively represent the distances from the action points of the attitude control engine and the orbit control engine thrust to the warhead, represents the distance from the center of mass to the warhead, represents the moment of inertia of the interceptor about the z-axis of the body coordinate system.

[0039] It should be noted that the first interference parameter, the second interference parameter, and the third interference parameter are composed of control input errors, aerodynamic parameter perturbations, measurement errors, unknown dynamic characteristics, external disturbances, etc.

[0040] In one embodiment, based on the angular acceleration calculation formula of the line-of-sight angle and the dynamic equation of the interceptor, a strongly coupled state-space equation is constructed, including: based on the angular acceleration calculation formula of the line-of-sight angle and the dynamic equation of the interceptor, define , , , and , and determine the strongly coupled state-space equation as: (6); wherein, represents the first derivative of represents the first derivative of represents the first derivative of , , , , , , , , , , , , , , and represent the interference terms.

[0041] That is, based on Formula (4) and Formula (5), the parameters are customized to obtain the strongly coupled state-space equation.

[0042] S103. According to the strongly coupled state-space equation, a high-order multi-dimensional sliding mode matrix is constructed, and based on the high-order multi-dimensional sliding mode matrix, a strong coupling control law for the attitude control engine and the orbit control engine of the interceptor is designed; the high-order multi-dimensional sliding mode matrix satisfies the field of view constraint of the strapdown seeker of the interceptor.

[0043] According to the requirement that the interceptor needs to accurately hit the target while satisfying the field of view constraint of the strapdown seeker of the interceptor, a high-order multi-dimensional sliding mode matrix is constructed S as follows: (7); where , S = 0 represents the sliding mode surface, represents that the interceptor can hit the target, represents that the target is located at the center of the field of view of the seeker.

[0044] Optionally, based on the high-order multi-dimensional sliding mode matrix, a strong coupling control law for the attitude control engine and the orbit control engine of the interceptor is designed, including: according to the high-order multi-dimensional sliding mode matrix, a reaching law is designed; substituting the high-order multi-dimensional sliding mode matrix into the reaching law to obtain the strong coupling control law for the attitude control engine and the orbit control engine of the interceptor.

[0045] Specifically, to control the high-order multi-dimensional sliding mode matrix S to converge to zero, a reaching law is designed as: (8); where and respectively represent the estimated value and the estimation error of , , ; , , , , , and are all positive constants.

[0046] Substituting the derivative of Formula (7) with respect to time into Formula (8), the strong coupling control law for the attitude control engine and the orbit control engine of the interceptor is obtained as: (9); where , , , , 。

[0047] S104. Solve the interference term in the strong coupling control law according to the stability condition and fixed-time convergence condition of the interceptor guidance and control system under attitude-orbit coupling to obtain the estimated value of the interference term.

[0048] The neural network is a radial basis neural network, which consists of an input layer, a hidden layer, and an output layer. Among them, the non-linear activation function of the hidden layer is as follows: (10); Where , , , , , represents the number of hidden layer nodes. represents the output of the th neuron in the hidden layer. represents and the Euclidean distance between them, is a positive constant representing the width of the Gaussian basis function, represents the center vector.

[0049] Define and , represents the th neuron's network weight, then the interference in the system can be expressed as: (11); Where represents the approximation error, represents the ideal weight. Assume , , and are all positive constants.

[0050] The radial basis neural network estimates by adjusting the actual weight , so there is: (12).

[0051] Define the error between the actual weight and the ideal weight, substitute (11) into (12) to get: (13).

[0052] The smaller means the smaller the approximation error of the neural network to , so construct the cost function as follows: (14); Wherein, .

[0053] Design an adaptive variation law using the gradient descent method, such that the gradient descends, that is , wherein, is the learning rate of the neural network, . Substituting (14) into it, we can get:

[0054] (15).

[0055] The learning rate in the neural network needs to meet the following two requirements: (1) Ensure the stability of the control system based on the neural network disturbance observer; (2) The neural network disturbance observer needs to synchronously approximate multiple mismatched disturbances within a fixed time.

[0056] Optionally, according to the stability condition and the fixed-time convergence condition of the interceptor guidance and control system under the combined attitude and trajectory, solve the disturbance term in the strong coupling control law to obtain an estimated value of the disturbance term, including: determining the constraint condition of the learning rate in the neural network model according to the stability condition and the fixed-time convergence condition; training the neural network model according to the constraint condition of the learning rate in the neural network model; inputting the relative distance between the interceptor and the target, the line-of-sight angle change rate of the interceptor, the body line-of-sight angle, and the pitch angle rate into the trained neural network model to obtain an estimated value of the disturbance term.

[0057] In one embodiment, determining the constraint condition of the learning rate in the neural network model according to the stability condition and the fixed-time convergence condition includes: determining the first constraint condition of the learning rate in the neural network model according to the stability condition; determining the second constraint condition of the learning rate in the neural network model according to the fixed-time convergence condition; determining the constraint condition of the learning rate in the neural network model according to the first constraint condition and the second constraint condition.

[0058] Optionally, determining the first constraint condition of the learning rate in the neural network model according to the stability condition includes: designing a Lyapunov function according to the stability condition, and calculating the first-order derivative of the Lyapunov function with respect to time; determining the first constraint condition under the condition that the first-order derivative of the Lyapunov function with respect to time satisfies less than or equal to 0.

[0059] The Lyapunov function is as follows: (16); Wherein, , , are all positive constants.​

[0060] Substituting formulas (8), (13), and (15) into the derivative of (16) with respect to time gives: (17).

[0061] Denote , when , , , , , always holds. At this time, the control system based on the neural network disturbance observer is stable, that is, the first constraint condition is: , , .

[0062] Optionally, according to the fixed-time convergence condition, determine the second constraint condition of the learning rate in the neural network model, including: calculating the derivative of the cost function in the neural network model with respect to time; determining the second constraint condition under the condition that the derivative of the cost function in the neural network model with respect to time satisfies the fixed-time convergence condition.

[0063] Based on formulas (13) and (15), the derivative of the cost function with respect to time can be written in the following form: (18).

[0064] Let satisfy the following inequality (19); where , and are both greater than 0, .

[0065] Substituting (19) into (18) gives: (20).

[0066] The establishment of formula (20) indicates that is fixed-time stable. At this time, the convergence time of is: (21).

[0067] is not affected by the real-time state and can be regulated by the parameters , and . At When the same parameters are selected, synchronous approximation of multiple non-matching interferences can be achieved.

[0068] Combining equations (17) and (19), the learning rate has the following constraint conditions: (22); Among them, the interference terms in the strong coupling control law include the first interference term , the second interference term and the third interference term , denotes the learning rate corresponding to the first interference term , denotes the learning rate corresponding to the second interference term , denotes the learning rate corresponding to the third interference term , , , are all positive constants, , and are both greater than 0, , denotes the output of the th neuron in the hidden layer of the neural network.

[0069] S105. Substitute the estimated value of the interference term and the state data of the interceptor into the strong coupling control law of the interceptor to obtain the lateral thrust perpendicular to the missile body axis generated by the attitude control engine and the trajectory control engine. Control the interceptor through the lateral thrust perpendicular to the missile body axis generated by the attitude control engine and the trajectory control engine.

[0070] Substitute the estimated value of the interference term and the state data of the interceptor into the strong coupling control law of the interceptor to obtain and , that is and .

[0071] The present invention is directed to a high-speed target interceptor under attitude and trajectory composite control, and proposes a control method for the interceptor under attitude and trajectory composite. By constructing a high-order multi-dimensional sliding mode control law, efficient utilization and compensation of the coupling effect are achieved, while saving engine fuel while improving control performance; combining the sliding mode control law and the fixed-time theory, stability conditions and fixed-time convergence conditions for the control system are proposed for the weight update law of the radial basis neural network. Under the premise of considering the stability of the control system, fixed-time convergence of the approximation error is achieved, and the response speed and control accuracy of the interceptor under complex interferences are improved.

[0072] The effectiveness of the present invention is verified through the following three parts of simulations: 1) Verification of the strong coupling control method; 2) Verification of the performance of the fixed-time neural network disturbance observer; 3) Verification of the strong coupling control method based on the fixed-time neural network disturbance observer.

[0073] 1) Verification of the strong coupling control method Under different degrees of coupling effects (reflected by different degrees of centroid drift), the control effects of the control method (SCC) of the interceptor under the combined attitude and trajectory proposed in the present invention are compared and tested with the traditional guidance-control loop separation method (guidance and control, GC). As Figure 3 、 Figure 4 and Table 1 show, where Figure 3 is a schematic diagram of the response curves of the body line-of-sight angle changing with time under different degrees of centroid drift for SCC and GC, Figure 3 in which the (a) figure is the response curve of the body line-of-sight angle changing with time under different degrees of centroid drift for the SCC method of the present invention, Figure 3 and the (b) figure in Figure 4 is the response curve of the body line-of-sight angle changing with time under different degrees of centroid drift for the traditional GC method; Figure 4 is a schematic diagram of the response curves of the pitch angle rate changing with time under different degrees of centroid drift for SCC and GC, Figure 4 in which the (a) figure is the response curve of the pitch angle rate changing with time under different degrees of centroid drift for the SCC method of the present invention,

[0074] Table 1 From Figure 3 and Figure 4 it can be seen that as the coupling effect intensifies, the state response curves under SCC almost coincide and finally converge to zero, while the control performance of GC significantly deteriorates as the coupling increases; analyzing the data in Table 1 shows that under different coupling effects, SCC can successfully intercept the target, and the consumption of the attitude and trajectory control thrust impulse is not much different, while the impulse consumed by GC increases with the intensification of coupling, and GC cannot successfully intercept the target when the coupling is severe. Based on the above simulation results, it can be known that the robustness of SCC to unknown coupling effects is significantly stronger than that of GC, and high-precision control under the combined attitude and trajectory can be achieved.

[0075] Performance verification of the fixed-time convergent neural network disturbance observer: The disturbance approximation performances of the disturbance observer based on the fixed-time convergent radial basis function neural network (FTRBFNN) proposed in the present invention and the disturbance observer based on the asymptotically convergent radial basis function neural network (RBFNN) were compared and tested.

[0076] As Figure 5 shown, Figure 5 Fig. is a schematic diagram of the state response curves under FTRBFNN and RBFNN provided by the present invention. Figure 5 In Figs. (a), (b), and (c), the response curves of the line-of-sight angular rate, body line-of-sight angle, and pitch angular rate with respect to time in FTRBFNN and RBFNN are respectively shown. It can be seen from Figure 5 that compared with RBFNN, under the action of FTRBFNN, the state response curves converge faster and the tracking errors are smaller, indicating that FTRBFNN can achieve fast estimation and compensation of disturbances, thereby improving the control accuracy and response speed of the interceptor.

[0077] Verification of the strong coupling control method based on the fixed-time neural network disturbance observer: The performance of the strong coupling control method based on the fixed-time neural network disturbance observer proposed in the present invention was tested through 300 Monte Carlo shooting tests. The test results are as Figure 6 shown, Figure 6 Fig. is a schematic diagram of the miss distance results of the Monte Carlo shooting of the control method of the interceptor under the combined attitude and orbit control provided by the present invention. It can be seen from Figure 6 that the average miss distance of the 300 Monte Carlo tests is 0.88 m, and there is only one interception failure, which proves that the strong coupling control method based on the fixed-time neural network disturbance observer has strong robustness and can achieve accurate interception of high-speed targets under complex disturbances.

[0078] The present invention is directed to a strongly coupled system under combined attitude and orbit control, and proposes a control method for an interceptor under combined attitude and orbit control. By utilizing the coupling effect between attitude control / orbit control, the control performance is improved and engine fuel is saved. For the weight update law of the neural network, stability conditions and fixed-time convergence conditions are proposed, forming a strong coupling control method based on the fixed-time neural network disturbance observer, realizing fast and synchronous approximation of unmatched disturbances, and effectively improving the control accuracy and response speed of the interceptor.

[0079] High-speed target interception missions have extremely high requirements for the control performance of interceptors. Existing research on integrated attitude and trajectory control treats attitude control and trajectory control as two relatively independent links, lacking in-depth analysis and effective utilization of the coupling effects caused by them, resulting in low control accuracy and poor robustness of the control system. The present invention proposes a control method for an interceptor under integrated attitude and trajectory control, which treats attitude control / trajectory control as a whole, introduces coupling effects into the control law, and effectively improves the control performance of the interceptor under integrated attitude and trajectory control. Moreover, due to the complex flight environment in the near space and the unknown coupling caused by integrated attitude and trajectory control, it is difficult to accurately model a high-speed target interceptor. In existing data-driven interference identification methods for low-precision models, there is a lack of research on identification speed regulation technology, and it is difficult to achieve fast and accurate estimation of mismatched interference in a strongly coupled system. The present invention proposes a fixed-time neural network interference observer and combines it with strong coupling control to achieve regulation of the interference identification speed, providing a technical approach for fast and synchronous estimation / compensation of multi-source and mismatched interference, and improving the control accuracy and response speed of a high-speed target interceptor under integrated attitude and trajectory control.

[0080] When applying the control method for an interceptor under integrated attitude and trajectory control provided by the present invention, it is not necessary to execute according to Figure 1 the order of the steps shown. The specific execution order of each step can be determined as needed, and the present invention does not limit this.

[0081] The above is the control method for an interceptor under integrated attitude and trajectory control provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding control device for an interceptor under integrated attitude and trajectory control, as Figure 7 shown.

[0082] Figure 7 This is a schematic diagram of a control device for an interceptor under integrated attitude and trajectory control provided by the present invention. The device 700 includes: A determination module 701, configured to determine a calculation formula for the angular acceleration of the line-of-sight angle between the interceptor and the target according to the relative kinematic equation of the interceptor and the target in the longitudinal plane.

[0083] A customization module 702, configured to construct a strongly coupled state-space equation according to the calculation formula for the angular acceleration of the line-of-sight angle and the dynamic equation of the interceptor.

[0084] A design module 703, configured to construct a high-order multi-dimensional sliding mode matrix according to the strongly coupled state-space equation, and design a strong coupling control law for the interceptor according to the high-order multi-dimensional sliding mode matrix; the high-order multi-dimensional sliding mode matrix satisfies the field-of-view constraint of the strapdown seeker of the interceptor.

[0085] A solution module 704 is configured to solve the interference term in the strong coupling control law according to the stability condition and the fixed-time convergence condition of the interceptor guidance and control system under the combined attitude and trajectory, so as to obtain an estimated value of the interference term.

[0086] An obtaining module 705 is configured to substitute the estimated value of the interference term and the state data of the interceptor into the strong coupling control law of the interceptor, so as to obtain the lateral thrusts generated by the attitude control engine and the trajectory control engine and perpendicular to the missile body axis.

[0087] A control module 706 is configured to control the interceptor by means of the lateral thrusts generated by the attitude control engine and the trajectory control engine and perpendicular to the missile body axis.

[0088] For the specific limitations of the control device of the interceptor under the combined attitude and trajectory, reference can be made to the limitations of the control method of the interceptor under the combined attitude and trajectory in the foregoing text, which will not be elaborated herein. Each module in the above control device of the interceptor under the combined attitude and trajectory can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor in the computer device in hardware form or independent of the processor, or stored in the memory in the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0089] The present invention also provides a computer-readable storage medium storing a computer program, and the computer program can be used to execute the Figure 1 control method of the interceptor under the combined attitude and trajectory provided above.

[0090] The present invention also provides Figure 8 a schematic structural diagram of the computer device shown in Figure 8 As shown, at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, other hardware required for other services may also be included. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the Figure 1 control method of the interceptor under the combined attitude and trajectory provided above.

[0091] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided by the present invention can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0092] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope recorded by the present invention.

Claims

1. A control method for an attitude-orbit composite interceptor, characterized in that: include: Based on the relative kinematic equation between the interceptor and the target in the longitudinal plane, determine the angular acceleration calculation formula of the line of sight angle between the interceptor and the target; According to the calculation formula of angular acceleration of the sight angle and the dynamic equation of the interceptor, a strongly coupled state space equation is constructed; According to the strongly coupled state space equation, a high-order multidimensional sliding mode matrix is ​​constructed, and according to the high-order multidimensional sliding mode matrix, a strongly coupled control law of the attitude control engine and the orbit control engine of the interceptor is designed; the high-order multidimensional sliding mode matrix satisfies the field of view constraint of the strapdown seeker of the interceptor; According to the stability condition and fixed time convergence condition of the interceptor guidance control system under attitude and orbit combination, the interference term in the strong coupling control law is solved and the estimated value of the interference term is obtained. Substituting the estimated value of the interference term and the state data of the interceptor into the strong coupling control law of the interceptor to obtain the lateral thrust perpendicular to the missile body axis generated by the attitude control engine and the orbit control engine; The interceptor is controlled by the lateral thrust perpendicular to the axis of the missile body generated by the attitude control engine and the orbit control engine.

2. The method according to claim 1, characterized in that: The angular acceleration calculation formula for determining the sight angle between the interceptor and the target based on the relative kinematic equation between the interceptor and the target in the longitudinal plane includes: Substituting the interceptor's ballistic inclination velocity calculation formula into the relative kinematic equation between the interceptor and the target in the longitudinal plane, the angular acceleration calculation formula of the sight angle is obtained; The relative kinematic equation between the interceptor and the target in the longitudinal plane is: ； in, and Represent the relative distance and sight angle between the interceptor and the target, respectively. express The first derivative with respect to time, represents the rate of change of sight angle, The first derivative with respect to time, and represent the ballistic inclination angles of the interceptor and the target respectively, and represent the speeds of the interceptor and target respectively; The ballistic inclination velocity calculation formula of the interceptor is: ； in, represents the interceptor's ballistic inclination velocity, The first derivative of represents the interceptor velocity vector, and They represent the lateral thrust perpendicular to the missile body axis generated by the attitude control engine and the orbit control engine, represents the angle of attack, represents the lift generated by aerodynamic forces, Indicates the quality of the interceptor; The angular acceleration calculation formula of the sight angle is: ； in, represents the angular acceleration of the sight angle, represents the first interference parameter, represents the acceleration due to gravity, Indicates the acceleration of the target.

3. The method according to claim 2, characterized in that The dynamic equation of the interceptor is: ； in, represents the interceptor's stereoscopic line of sight angle, express The first derivative of represents the pitch rate of the interceptor, represents the second interference parameter, represents the third interference parameter, express The first derivative with respect to time, Indicates dynamic pressure, represents the maximum cross-sectional area of ​​the interceptor, Represents the length of the interceptor, and Respectively, relative to and The pitching moment coefficient, and They represent the distances from the thrust points of the attitude control engine and orbit control engine to the warhead, represents the distance from the center of mass to the projectile, Represents the moment of inertia of the interceptor around the z-axis of the missile body coordinate system.

4. The method according to claim 3, characterized in that The strong coupling state space equation is constructed based on the angular acceleration calculation formula of the sight angle and the dynamic equation of the interceptor, including: Based on the angular acceleration calculation formula of the line of sight angle and the dynamic equation of the interceptor, define , , , and , the strongly coupled state space equation is determined as: ； in, express The first derivative of express The first derivative of express The first derivative of , , , , , , , , , , , , , , and Represents interference terms.

5. The method according to claim 4, characterized in that The method of designing a strong coupling control law of the attitude control engine and the orbit control engine of the interceptor according to the high-order multi-dimensional sliding mode matrix includes: Designing a reaching law according to the high-order multi-dimensional sliding mode matrix; Substituting the high-order multi-dimensional sliding mode matrix into the reaching law, a strong coupling control law of the attitude control engine and the orbit control engine of the interceptor is obtained; The high-order multidimensional sliding mode matrix for: ； The reaching law for: ； in, and Respectively represent The estimated value and estimation error of , ; , , , , , and All are normal numbers; The strong coupling control law of the attitude control engine and orbit control engine of the interceptor for: ； in, , , , , .

6. The method according to claim 5, characterized in that According to the stability condition and fixed time convergence condition of the interceptor guidance control system under attitude and orbit combination, the interference term in the strong coupling control law is solved to obtain the estimated value of the interference term, including: Determine the constraints on the learning rate in the neural network model based on stability conditions and fixed time convergence conditions; According to the constraints of the learning rate in the neural network model, the neural network model is trained; The relative distance between the interceptor and the target, the interceptor's line of sight angle change rate, volume line of sight angle and pitch angle rate are input into the trained neural network model to obtain the estimated value of the interference term.

7. The method according to claim 6, characterized in that The constraint conditions of the learning rate in the neural network model are determined according to the stability condition and the fixed time convergence condition, including: According to the stability condition, the first constraint condition of the learning rate in the neural network model is determined; According to the fixed time convergence condition, a second constraint condition of the learning rate in the neural network model is determined; According to the first constraint condition and the second constraint condition, a constraint condition of the learning rate in the neural network model is determined.

8. The method according to claim 7, characterized in that The first constraint condition of the learning rate in the neural network model is determined according to the stability condition, including: According to the stability conditions, a Lyapunov function is designed; calculating the first-order derivative of the Lyapunov function with respect to time; Under the condition that the first-order derivative of the Lyapunov function with respect to time is less than or equal to 0, the first constraint condition is determined.

9. The method according to claim 7, characterized in that: The second constraint condition for determining the learning rate in the neural network model according to the fixed time convergence condition includes: Calculating the derivative of the cost function in the neural network model with respect to time; The second constraint condition is determined under the condition that the derivative of the cost function with respect to time in the neural network model satisfies a fixed time convergence condition.

10. The method according to claim 7, characterized in that The first constraint condition is: , , ; The second constraint is: ; The constraints on the learning rate are: ； The interference term in the strong coupling control law includes the first interference term , the second interference and the third distractor , The first interference term The corresponding learning rate is Represents the second interference term The corresponding learning rate is Represents the third interference term The corresponding learning rate is , , are all normal numbers, , and are greater than 0, , Represents the hidden layer in the neural network The output of a neuron.

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