Temperature and speed intermittent control method for hypersonic rocket vehicle

Abstract

The invention discloses a temperature and speed intermittent control method for a hypersonic rocket vehicle. The method comprises the following steps: S1, establishing a dynamic model comprising a speed subsystem and a temperature subsystem of the hypersonic rocket vehicle; introducing an error variable, and converting the kinetic model into an error system model; establishing a coupling fuzzy error system model by combining a T-S fuzzy model and constructing a coupling state variable; s2, designing a discontinuous state observer and an intermittent feedback control signal of a hypersonic rocket vehicle system based on the coupling fuzzy error system model of the hypersonic rocket vehicle; in a stability analysis process, determining design parameters of the intermittent feedback control signal; and S3, performing intermittent control on the hypersonic rocket vehicle by using the intermittent feedback control signal. According to the control method, the control problem of the hypersonic rocket vehicle under the conditions that the state information cannot be completely measured and the communication bandwidth is limited is solved, and the control performance of the system can be ensured while the communication burden of the system can be effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of hypersonic rocket vehicles, and in particular to a method for intermittently controlling the temperature and speed of a hypersonic rocket vehicle. Background Art

[0002] Hypersonic rocket vehicles can reach the target area in a very short time. This rapid response capability has important strategic significance in national defense and security. Therefore, hypersonic rocket vehicles have been widely studied in the fields of advanced flight technology, national defense and security needs, and the development direction of aerospace engineering. When a hypersonic rocket vehicle is running at hypersonic speed, extreme air friction heat will be generated on the outside, causing the material to heat up rapidly, and the air flow at this time has strong nonlinear characteristics, such as turbulence, shock waves, etc., which may affect the stability of the system. At this time, in order to ensure the stability of the system, it is necessary to control the system.

[0003] The control system of a hypersonic rocket vehicle has the following difficulties in construction:

[0004] (1) The prior art proposes to model the hypersonic rocket vehicle system using a system consisting of a set of ordinary differential equations and partial differential equations, and proposes a series of control strategies for the temperature and speed of the hypersonic rocket vehicle, which can achieve the control of the temperature and speed of the hypersonic rocket vehicle to a certain extent, but this method undoubtedly increases the complexity of the calculation.

[0005] (2) In actual engineering, due to the limitations of factors such as system communication bandwidth, the system may experience system information loss and delay during the continuous control process, resulting in a decrease in system control accuracy and damage to stability.

[0006] (3) Due to the complex external environment and some nonlinear characteristics of the hypersonic rocket vehicle system, it is difficult to ensure the stability of the control system. Summary of the invention

[0007] The purpose of the present invention is to propose a method for intermittently controlling the temperature and speed of a hypersonic rocket vehicle, which solves the control problem of a hypersonic rocket vehicle when the state information cannot be fully measured and the communication bandwidth is limited. It can effectively reduce the communication burden of the system while ensuring the control performance of the system.

[0008] The technical solution adopted by the present invention is: a method for intermittently controlling the temperature and speed of a hypersonic rocket vehicle, comprising the following steps:

[0009] S1. Establish a dynamic model including the speed subsystem and temperature subsystem of the hypersonic rocket vehicle;

[0010] Introducing error variables to transform the dynamic model into an error system model of a hypersonic rocket vehicle;

[0011] Based on the TS fuzzy model, the nonlinear part in the error system model is linearized to generate a fuzzy error system model;

[0012] By constructing coupled state variables, a coupled fuzzy error system model of speed and temperature is established;

[0013] S2. Based on the coupled fuzzy error system model of the hypersonic rocket vehicle, a discontinuous state observer for estimating the system state of the hypersonic rocket vehicle and an intermittent feedback control signal for periodically controlling the hypersonic rocket vehicle are designed;

[0014] Performing stability analysis on the coupled fuzzy error system model of the hypersonic rocket vehicle, and determining the design parameters of the intermittent feedback control signal according to the stability;

[0015] S3. Use the intermittent feedback control signal after substituting the design parameters to intermittently control the speed and temperature of the hypersonic rocket vehicle.

[0016] As a preferred solution, the dynamic model of the hypersonic rocket vehicle is:

[0017]

[0018] Its boundary conditions are expressed as:

[0019] ξ s (0,t)=ξ s (Γ,t)=0

[0020] Among them, χ(t) represents the displacement of the hypersonic rocket vehicle at time t, χ t (t) and χ tt (t) represent the first-order derivative and the second-order derivative of χ(t) with respect to time, respectively; ξ(s,t) represents the temperature of the hypersonic rocket vehicle at the spatial position s at time t, ξ t (s,t) and ξ tt (s, t) respectively represent the first-order derivative and the second-order derivative of ξ(s, t) with respect to time; s∈[0,Γ] represents the spatial position; ξ s (0,t) and ξ s (Γ, t) represents the first-order derivative of ξ(s, t) at spatial position 0 and the first-order derivative of ξ(s, t) at spatial position Γ, respectively; a1 and a2 are controller coefficients, Δ1(t) and Δ2(s, t) represent the control input of the hypersonic rocket vehicle ODE velocity subsystem at time t and the control input of the hypersonic rocket vehicle PDE temperature subsystem at spatial position s at time t, respectively; m represents the mass of the hypersonic rocket vehicle; μ aIndicates the air resistance coefficient; μ v represents the viscous friction coefficient; d m Indicates material density; s h represents the specific heat capacity of the material; ε represents the singular perturbation parameter, and 0<ε<<1; c t represents thermal conductivity; p represents circumference; c h represents the convective heat transfer coefficient; a c represents the cross-sectional area; d v represents dynamic viscosity; e m Indicates the emissivity of the material; b c represents the Boltzmann constant; ξ1 represents the temperature of the medium around the surface; ξ2 represents the temperature far away in the direction of the surface normal.

[0021] As a preferred solution, the error system model of the hypersonic rocket vehicle is:

[0022]

[0023] Its boundary conditions are expressed as:

[0024] Ξ s (0,t)=Ξ s (Γ,t)=0

[0025] The system output is expressed as:

[0026] y1(t)=c1x(t)

[0027] y2(s,t)=c2Ξ(s,t)

[0028] where x(t) represents the velocity error of the hypersonic rocket vehicle at time t, and χ z represents the steady-state speed of the hypersonic rocket vehicle during its travel, and satisfies u1(t)=Δ1(t)-u 1z ; is a positive constant to be designed, u 1z represents the steady-state control input of speed; x t (t) represents the first-order derivative of x(t) with respect to time; G1(x(t)) and G3(x(t)) represent nonlinear functions with respect to the error x(t); b1, b2, c1, and c2 are constants; Ξ(s, t) represents the temperature error of the hypersonic rocket vehicle at time t and spatial position s, and ξ z It represents the steady-state temperature of the hypersonic rocket vehicle during its travel; is a positive constant to be designed;

[0029] Steady-state temperature ξ z satisfy u 2z represents the steady-state control input of temperature; u2(t) = Δ2(t) - u 2z ;Ξ t (s,t) and Ξ ss (s, t) represents the first-order derivative of Ξ(s, t) with respect to time and the second-order derivative with respect to space; G2(Ξ(s, t)) represents a nonlinear function with respect to Ξ(s, t); r represents the reaction diffusion coefficient of the partial differential equation subsystem of the hypersonic rocket vehicle, and r>0; Ξ(0, t) and Ξ(Γ, t) represent the temperature error of the hypersonic rocket vehicle at the time t and the spatial position 0 and the temperature error at the time t and the spatial position Γ, respectively; Ξ s (0,t) and Ξ s (Γ, t) represents the first-order derivative of Ξ(s, t) with respect to space at spatial position 0 and the first-order derivative with respect to space at spatial position Γ, respectively; y1(t) and y2(s, t) represent the outputs of the hypersonic rocket vehicle system.

[0030] As a preferred solution, the fuzzy error system model of the hypersonic rocket vehicle is:

[0031]

[0032] Where: h i and They represent the membership function of the ODE velocity subsystem and the PDE temperature subsystem respectively; A i , B i and C l are real numbers, i = 1, 2, ..., n, l = 1, 2, ..., n.

[0033] As a preferred solution, the coupled fuzzy error system model of the hypersonic rocket vehicle is:

[0034]

[0035] in, and express First derivative with respect to time and second derivative with respect to space; Z -1 (ε) represents the inverse matrix of the matrix Z(ε).

[0036] As a preferred solution, the discontinuous state observer of the hypersonic rocket vehicle is:

[0037]

[0038] in, express The estimated value of and denote the estimated values ​​of x(t) and Ξ(s,t), respectively. and express First derivative with respect to time and second derivative with respect to space; express The estimation error of represents the estimation error of x(t), represents the estimation error of Ξ(s,t); k is a natural number; ω represents the period of intermittent observation; σ represents the control time of the system in one period; L O and L P is the observer gain to be designed, c3 and c4 are positive constants.

[0039] As a preferred solution, the intermittent feedback control signal of the designed hypersonic rocket vehicle is:

[0040]

[0041] u1(t)=u2(s,t)=0,t∈(kω+σ,(k+1)ω]

[0042] Where K1 and K2 are the controller gains to be designed. The designed control signal is an intermittent state feedback control signal. Since the state variables of the system cannot be directly measured from outside the system, this method estimates the state of the system through a discontinuous state observer, and then effectively improves the performance of the system through state feedback control.

[0043] As a preferred solution, a Lyapunov function is established, and the stability analysis of the hypersonic rocket vehicle is carried out according to the derivative of the Lyapunov function with respect to time, so as to determine the design parameters of the observer gain and controller gain of the system under the stable state, as well as the minimum control time ratio.

[0044] As a preferred solution, the established Lyapunov function V(t) is:

[0045]

[0046] Where, ds represents the differential operator;

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The present invention couples the states of the systems together by constructing coupling vectors and rewrites the original system into a coupled system, which greatly reduces the computational complexity of the controller design process;

[0049] 2. Compared with the continuous control strategy, the present invention combines an intermittent control scheme, which can reduce the communication pressure of the system while controlling the temperature and speed of the hypersonic rocket vehicle.

[0050] 3. In addition, the present invention takes into account the situation that the state information of the system cannot be fully measured, designs a discontinuous state observer for the system, and then applies intermittent control to the system based on the discontinuous state observer. The method of the present invention can realize the control of the process object, has good robustness and stability, and can effectively improve economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0052] Figure 1 This is a simulation diagram of the velocity error of a hypersonic rocket vehicle without control action;

[0053] Figure 2 This is a simulation diagram of the temperature error of a hypersonic rocket vehicle without control action;

[0054] Figure 3 It is a simulation diagram of the speed error of the hypersonic rocket vehicle under the control method of the present invention;

[0055] Figure 4 It is a temperature error simulation diagram of a hypersonic rocket vehicle under the control method of the present invention;

[0056] Figure 5 It is a simulation diagram of the observation error of the discontinuous state observer for the ODE velocity subsystem of the hypersonic rocket vehicle under the control method of the present invention;

[0057] Figure 6 It is a simulation diagram of the observation error of the discontinuous state observer for the PDE temperature subsystem of the hypersonic rocket vehicle under the control method of the present invention;

[0058] Figure 7 It is a simulation diagram of intermittent control signals of the ODE speed subsystem of a hypersonic rocket vehicle under the control method of the present invention;

[0059] Figure 8It is a simulation diagram of the intermittent control signal of the PDE temperature subsystem of the hypersonic rocket vehicle under the control method of the present invention. DETAILED DESCRIPTION

[0060] The present invention is described in detail below by way of exemplary embodiments. However, it should be understood that, without further description, elements, structures and features in one embodiment may also be beneficially combined in other embodiments.

[0061] It should be noted that: unless otherwise defined, the technical terms or scientific terms used in this document shall have the usual meanings understood by people with ordinary skills in the field to which the invention belongs. The words "one", "an" or "the" and the like used in the patent application specification and claims of the present invention do not express quantity restrictions, but indicate the existence of at least one; the words "first", "second" and "third" used in this document shall not be regarded as restrictions on the order of components, but are only used to distinguish different components; words such as "include" or "comprise" and the like indicate that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, but do not exclude other elements or objects with the same function.

[0062] In order to more clearly describe the temperature and speed intermittent control method of a hypersonic rocket vehicle, combined with the attached Figure 1-8 Describe this embodiment:

[0063] A method for intermittently controlling temperature and speed of a hypersonic rocket vehicle comprises the following steps:

[0064] S1. Establish a dynamic model including the speed subsystem and temperature subsystem of the hypersonic rocket vehicle;

[0065] S1.1. Establish the following dynamic model of the hypersonic rocket vehicle:

[0066]

[0067] Its boundary conditions are expressed as:

[0068] ξ s (0,t)=ξ s (Γ,t)=0 (2)

[0069] Among them, χ(t) represents the displacement of the hypersonic rocket vehicle at time t, χ t (t) and χ tt (t) represent the first-order derivative and the second-order derivative of χ(t) with respect to time, respectively; ξ(s,t) represents the temperature of the hypersonic rocket vehicle at the spatial position s at time t, ξ t (s,t) and ξtt (s, t) respectively represent the first-order derivative and the second-order derivative of ξ(s, t) with respect to time; s∈[0,Γ] represents the spatial position; ξ s (0,t) and ξ s (Γ, t) represents the first-order derivative of ξ(s, t) at spatial position 0 and the first-order derivative of ξ(s, t) at spatial position Γ, respectively; a1 and a2 are controller coefficients, Δ1(t) and Δ2(s, t) represent the control input of the hypersonic rocket vehicle ODE velocity subsystem at time t and the control input of the hypersonic rocket vehicle PDE temperature subsystem at spatial position s at time t, respectively; m represents the mass of the hypersonic rocket vehicle; μ a Indicates the air resistance coefficient; μ v represents the viscous friction coefficient; d m Indicates material density; s h represents the specific heat capacity of the material; ε represents the singular perturbation parameter, and 0<ε<<1; c t represents thermal conductivity; p represents circumference; c h represents the convective heat transfer coefficient; a c represents the cross-sectional area; d v represents dynamic viscosity; e m Indicates the emissivity of the material; b c represents the Boltzmann constant; ξ1 represents the temperature of the medium around the surface; ξ2 represents the temperature far away in the direction of the surface normal.

[0070] S1.2. Introduce error variables and transform the dynamic model into an error system model of the hypersonic rocket vehicle;

[0071] The error system model of the hypersonic rocket vehicle is:

[0072]

[0073] Its boundary conditions are expressed as:

[0074] Ξ s (0,t)=Ξ s (Γ,t)=0 (4)

[0075] The system output is expressed as:

[0076] y1(t)=c1x(t) (5)

[0077] y2(s,t)=c2Ξ(s,t) (6)

[0078] where x(t) represents the velocity error of the hypersonic rocket vehicle at time t, and χ zrepresents the steady-state speed of the hypersonic rocket vehicle during its travel, and satisfies u1(t)=Δ1(t)-u 1z ; is a positive constant to be designed, u 1z represents the steady-state control input of speed; x t (t) represents the first-order derivative of x(t) with respect to time; G1(x(t)) and G3(x(t)) represent nonlinear functions with respect to the error x(t); b1, b2, c1, and c2 are constants; Ξ(s, t) represents the temperature error of the hypersonic rocket vehicle at time t and spatial position s, and ξ z It represents the steady-state temperature of the hypersonic rocket vehicle during its travel; is a positive constant to be designed;

[0079] Steady-state temperature ξ z satisfy u 2z represents the steady-state control input of temperature; u2(t) = Δ2(t) - u 2z ;Ξ t (s,t) and Ξ ss (s, t) represents the first-order derivative of Ξ(s, t) with respect to time and the second-order derivative with respect to space; G2(Ξ(s, t)) represents a nonlinear function with respect to Ξ(s, t); r represents the reaction diffusion coefficient of the partial differential equation subsystem of the hypersonic rocket vehicle, and r>0; Ξ(0, t) and Ξ(Γ, t) represent the temperature error of the hypersonic rocket vehicle at the time t and the spatial position 0 and the temperature error at the time t and the spatial position Γ, respectively; Ξ s (0,t) and Ξ s (Γ, t) represents the first-order derivative of Ξ(s, t) with respect to space at spatial position 0 and the first-order derivative with respect to space at spatial position Γ, respectively; y1(t) and y2(s, t) represent the outputs of the hypersonic rocket vehicle system.

[0080] S1.3, based on the TS fuzzy model, linearizing the nonlinear part in the error system model, thereby generating a fuzzy error system model;

[0081] The fuzzy error system model of the hypersonic rocket vehicle is:

[0082]

[0083] Where: h i and They represent the membership function of the ODE velocity subsystem and the PDE temperature subsystem respectively; A i, B i and C l are real numbers, i = 1, 2, ..., n, l = 1, 2, ..., n.

[0084] S1.4. Establish a coupled fuzzy error system model of speed and temperature by constructing coupled state variables;

[0085] The coupled fuzzy error system model of the hypersonic rocket vehicle is:

[0086]

[0087] in, and express First derivative with respect to time and second derivative with respect to space; Z -1 (ε) represents the inverse matrix of the matrix Z(ε).

[0088] S2. Based on the coupled fuzzy error system model of the hypersonic rocket vehicle, a discontinuous state observer for estimating the system state of the hypersonic rocket vehicle and an intermittent feedback control signal for periodically controlling the hypersonic rocket vehicle are designed;

[0089] S2.1. Establish the following discontinuous state observer:

[0090]

[0091] in, express The estimated value of and denote the estimated values ​​of x(t) and Ξ(s,t), respectively. and express First derivative with respect to time and second derivative with respect to space; express The estimation error of represents the estimation error of x(t), represents the estimation error of Ξ(s,t); k is a natural number; ω represents the period of intermittent observation; σ represents the control time of the system in one period; L O and L P is the observer gain to be designed, c3 and c4 are positive constants.

[0092] The intermittent feedback control signal of the designed hypersonic rocket vehicle is:

[0093]

[0094] u1(t)=u2(s,t)=0,t∈(kω+σ,(k+1)ω] (11)

[0095] Where K1 and K2 are the controller gains to be designed; σ is the control time within one cycle; ω is the time of one cycle.

[0096] S2.2 Perform stability analysis on the coupled fuzzy error system model of the hypersonic rocket vehicle and determine the design parameters of the intermittent feedback control signal based on the stability;

[0097] Specifically, a Lyapunov function is established, and the stability analysis of the hypersonic rocket vehicle is performed according to the derivative of the Lyapunov function with respect to time, and the design parameters of the observer gain and the controller gain of the system in a stable state, as well as the minimum control time ratio, are determined.

[0098] The specific process is as follows:

[0099] The established Lyapunov function V(t) is:

[0100]

[0101] Where, ds represents the differential operator;

[0102] Furthermore, we can get the derivative of the Lyapunov function with respect to time:

[0103] When t∈(kω,kω+σ]:

[0104]

[0105] in, I represents the 4th-order identity matrix, diag{} represents the diagonal matrix, τ1 is a positive constant.

[0106] It can be obtained that when t∈(kω,kω+σ] and diag{Ψ 11 ,Ψ 22 ,Ψ 33 ,Ψ 44}≤0,

[0107]

[0108] in,

[0109] π is the ratio of a circle to its circumference.

[0110] In addition, when t∈(kω+σ,(k+1)ω]:

[0111]

[0112] in,

[0113] It can be obtained that when t∈(kω+σ,(k+1)ω] and hour,

[0114]

[0115] τ2 is a positive constant.

[0116] Integrating (14) from kω to t yields:

[0117]

[0118] Integrating (16) from kω+σ to t yields:

[0119]

[0120] Furthermore, substituting t∈(kω,kω+σ] and t=kω+σ into (17), and substituting t∈(kω+σ,(k+1)ω] and t=(k+1)ω into (18), and then summarizing the rules when k=0,1,...,k by mathematical induction, we can get the following results:

[0121] When diag{Ψ 11 ,Ψ 22 ,Ψ 33 ,Ψ 44}≤0, When , the Lyapunov function satisfies:

[0122] V(t)≤V(0)e -γ(t-σ) (19)

[0123] V(0) is the value of V(t) at t = 0; When γ>0, the system is exponentially stable, so we can further obtain that the system control time ratio Also need to satisfy

[0124]

[0125] S3. Use the intermittent feedback control signal after substituting the design parameters to intermittently control the speed and temperature of the hypersonic rocket vehicle.

[0126] In order to illustrate in detail the control effect of the temperature and speed intermittent control method of the hypersonic rocket vehicle based on the discontinuous state observer of the present invention, the temperature and speed intermittent control method of the hypersonic rocket vehicle based on the discontinuous state observer is simulated in MATLAB.

[0127] The specific parameters of the hypersonic rocket vehicle are: m = 10kg, μ a =0.01N·s 2 / m 2 , μ v =0.01N·s / m,d v =1kg / m·s,d m =7865kg / m 3 ,s h =0.46 kj / (kg·K), e m =0.965, b c =5.669×10 -8 W / (m·K 4 ), c t =19W / (m·K), a c =1m 2 , p = 1.3716m, c h =20W / (m·K), ξ1=100K, ξ2=20K, χ z =20,ξ z =40, Γ=1.

[0128] The initial conditions are: x(0)=-1.5, ξ(s,0)=0.5cos(πs).

[0129] Here, cos represents the cosine function.

[0130] The error transformation of the dynamic model can be obtained:

[0131] x t (t) = δ1x 2 (t)+δ2x(t)+δ3a1u1(t);

[0132]

[0133] in,

[0134] The velocity error simulation diagram of the hypersonic rocket vehicle without control is shown in the figure below. Figure 1 As shown in the figure, the temperature error simulation diagram of the hypersonic rocket vehicle without control is as follows Figure 2 shown.

[0135] from Figure 1 and Figure 2 It can be seen that without control, the speed error and temperature error of the hypersonic rocket vehicle cannot converge, that is, the system cannot be stable, so it is necessary to apply appropriate control to the system.

[0136] Define υ(t) = x(t) and As the premise variable, and given x(t)∈[-2,2] and Ξ(s,t)∈[-1,1], we can get υ1=-2, υ2=2, and

[0138] Furthermore, the following membership function can be obtained:

[0139] h2(υ(t))=1-h1(υ(t))

[0140]

[0141] Furthermore, by solving two linear matrix inequalities diag{Ψ 11 ,Ψ 22 ,Ψ 33 ,Ψ 44}≤0 and According to the results, some parameters of the present invention are designed as K1 = -7.4532, K2 = -9.7268, τ1 = 0.0607, τ2 = 0.0530, L O =0.6247, L P =0.0514.

[0143] Furthermore, the relevant parameters are substituted into the result obtained by formula (19), and then σ = 0.605s, ω = 1.25s are selected as the control time within a cycle and the time of a cycle, and c1 = c2 = 1 is designed. So far, the three prerequisites for the exponential stability of the system have been met.

[0144] Then, under the action of the designed discontinuous state observer (9) and intermittent control signals (10)-(11), the velocity error simulation diagram of the hypersonic rocket vehicle is shown as follows: Figure 3 As shown in the figure, the temperature error simulation diagram of the hypersonic rocket vehicle is as follows Figure 4 The simulation diagram of the observation error of the discontinuous observer for the ODE velocity subsystem is shown in Figure 5 As shown; the observation error simulation diagram of the discontinuous observer for the PDE temperature subsystem is shown in Figure 6 As shown; the simulation diagram of intermittent control signal of the ODE speed subsystem of the hypersonic rocket vehicle is as follows Figure 7The simulation diagram of the intermittent control signal of the PDE temperature subsystem of the hypersonic rocket vehicle when the spatial positions are 0.2, 0.4, 0.6, and 0.8 respectively is shown in Figure 8 shown.

[0145] according to Figure 3 and Figure 4 It can be found that under the control method designed by the present invention, the speed error and temperature error of the hypersonic rocket vehicle finally converge to near 0 (that is, the speed and temperature of the hypersonic rocket vehicle finally stabilize near the expected value). Therefore, the temperature and speed intermittent control method of the hypersonic rocket vehicle based on the discontinuous state observer designed by the present invention is effective, that is, the speed and temperature intermittent control of the hypersonic rocket vehicle can be realized.

[0146] The parts not described in detail in the above embodiments are prior art.

[0147] It should be noted that although the present invention is described by the above embodiments, the present invention may also have other various embodiments. Without departing from the spirit and scope of the present invention, it is obvious that those skilled in the art may make various corresponding changes and deformations to the present invention, but these changes and deformations should all fall within the scope of protection of the appended claims of the present invention and their equivalents.

Claims

1. A method for intermittently controlling temperature and speed of a hypersonic rocket vehicle, characterized in that: The following steps are involved: S1. Establish a dynamic model including the speed subsystem and temperature subsystem of the hypersonic rocket vehicle; Introducing error variables to transform the dynamic model into an error system model of a hypersonic rocket vehicle; Based on the TS fuzzy model, the nonlinear part in the error system model is linearized to generate a fuzzy error system model; By constructing coupled state variables, a coupled fuzzy error system model of speed and temperature is established; S2. Based on the coupled fuzzy error system model of the hypersonic rocket vehicle, a discontinuous state observer for estimating the system state of the hypersonic rocket vehicle and an intermittent feedback control signal for periodically controlling the hypersonic rocket vehicle are designed; Performing stability analysis on the coupled fuzzy error system model of the hypersonic rocket vehicle, and determining the design parameters of the intermittent feedback control signal according to the stability; S3. Use the intermittent feedback control signal after substituting the design parameters to intermittently control the speed and temperature of the hypersonic rocket vehicle.

2. The method for intermittently controlling temperature and speed of a hypersonic rocket vehicle according to claim 1, characterized in that: The dynamic model of the hypersonic rocket vehicle is: Its boundary conditions are expressed as: x s (0,t)=ξ s (Γ,t)=0 Among them, χ(t) represents the displacement of the hypersonic rocket vehicle at time t, χ t (t) and χ tt (t) represent the first-order derivative and the second-order derivative of χ(t) with respect to time, respectively; ξ(s,t) represents the temperature of the hypersonic rocket vehicle at the spatial position s at time t, ξ t (s,t) and ξ tt (s, t) respectively represent the first-order derivative and the second-order derivative of ξ(s, t) with respect to time; s∈[0,Γ] represents the spatial position; ξ s (0,t) and ξ s (Γ, t) represents the first-order derivative of ξ(s, t) at spatial position 0 and the first-order derivative of ξ(s, t) at spatial position Γ, respectively; a1 and a2 are controller coefficients, Δ1(t) and Δ2(s, t) represent the control input of the hypersonic rocket vehicle ODE velocity subsystem at time t and the control input of the hypersonic rocket vehicle PDE temperature subsystem at spatial position s at time t, respectively; m represents the mass of the hypersonic rocket vehicle; μ a Indicates the air resistance coefficient; μ v represents the viscous friction coefficient; d m Indicates material density; s h represents the specific heat capacity of the material; ε represents the singular perturbation parameter, and 0<ε<<1; c t represents thermal conductivity; p represents circumference; c h represents the convective heat transfer coefficient; a c represents the cross-sectional area; d v represents dynamic viscosity; e m Indicates the emissivity of the material; b c represents the Boltzmann constant; ξ1 represents the temperature of the medium around the surface; ξ2 represents the temperature far away in the direction of the surface normal.

3. The temperature and speed intermittent control method of a hypersonic rocket vehicle according to claim 2, characterized in that: The error system model of the hypersonic rocket vehicle is: Its boundary conditions are expressed as: X s (0,t)=Ξ s (Γ,t)=0 The system output is expressed as: y1(t)=c1x(t) y2(s,t)=c2Ξ(s,t) where x(t) represents the velocity error of the hypersonic rocket vehicle at time t, and χ z represents the steady-state speed of the hypersonic rocket vehicle during its travel, and satisfies u1(t)=Δ1(t)-u 1z ; is a positive constant to be designed, u 1z represents the steady-state control input of speed; x t (t) represents the first-order derivative of x(t) with respect to time; G1(x(t)) and G3(x(t)) represent nonlinear functions with respect to the error x(t); b1, b2, c1, and c2 are constants; Ξ(s, t) represents the temperature error of the hypersonic rocket vehicle at time t and spatial position s, and ξ z It represents the steady-state temperature of the hypersonic rocket vehicle during its travel; is a positive constant to be designed; Steady state temperature ξ z satisfy u 2z represents the steady-state control input of temperature; u2(t) = Δ2(t) - u 2z ;Ξ t (s,t) and Ξ ss (s, t) represents the first-order derivative of Ξ(s, t) with respect to time and the second-order derivative with respect to space; G2(Ξ(s, t)) represents a nonlinear function with respect to Ξ(s, t); r represents the reaction diffusion coefficient of the partial differential equation subsystem of the hypersonic rocket vehicle, and r>0; Ξ(0, t) and Ξ(Γ, t) represent the temperature error of the hypersonic rocket vehicle at the time t and the spatial position 0 and the temperature error at the time t and the spatial position Γ, respectively; Ξ s (0,t) and Ξ s (Γ, t) represents the first-order derivative of Ξ(s, t) with respect to space at spatial position 0 and the first-order derivative with respect to space at spatial position Γ, respectively; y1(t) and y2(s, t) represent the outputs of the hypersonic rocket vehicle system.

4. The method for intermittently controlling temperature and speed of a hypersonic rocket vehicle according to claim 3, characterized in that: The fuzzy error system model of the hypersonic rocket vehicle is: Where: h i and They represent the membership function of the ODE velocity subsystem and the PDE temperature subsystem respectively; A i , B i and C l are real numbers, i = 1, 2, ..., n, l = 1, 2, ..., n.

5. The method for intermittently controlling temperature and speed of a hypersonic rocket vehicle according to claim 4, characterized in that: The coupled fuzzy error system model of the hypersonic rocket vehicle is: in, and express First derivative with respect to time and second derivative with respect to space; Z -1 (ε) represents the inverse matrix of the matrix Z(ε).

6. The method for intermittently controlling temperature and speed of a hypersonic rocket vehicle according to claim 5, characterized in that: The discontinuous state observer of the hypersonic rocket vehicle is: in, express The estimated value of and denote the estimated values ​​of x(t) and Ξ(s,t), respectively. and express First derivative with respect to time and second derivative with respect to space; express The estimation error of represents the estimation error of x(t), represents the estimation error of Ξ(s,t); k is a natural number; ω represents the period of intermittent observation; σ represents the control time of the system in one period; L O and L P is the observer gain to be designed, c3 and c4 are positive constants.

7. The method for intermittently controlling temperature and speed of a hypersonic rocket vehicle according to claim 6, characterized in that: The intermittent feedback control signal of the designed hypersonic rocket vehicle is: u1(t)=u2(s,t)=0,t∈(kω+σ,(k+1)ω] Where K1 and K2 are the controller gains to be designed.

8. The method for intermittently controlling temperature and speed of a hypersonic rocket vehicle according to claim 7, characterized in that: The Lyapunov function is established, and the stability analysis of the hypersonic rocket vehicle is carried out according to the derivative of the Lyapunov function with respect to time. The design parameters of the observer gain and controller gain of the system under the stable state, as well as the minimum control time ratio are determined.

9. The method for intermittently controlling temperature and speed of a hypersonic rocket vehicle according to claim 8, characterized in that: The established Lyapunov function V(t) is: Where, ds represents the differential operator;

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