A new criterion for aircraft engine control system based on fault-tolerant synchronous control

Abstract

The present invention discloses a new criterion for an aircraft engine control system based on fault-tolerant synchronous control. The method adopts a proportional-integral intermediate observer method to discuss a switching network system with unknown states and unknown faults. In addition, by constructing a segmented controller containing estimated states and faults, the estimated error system is guaranteed to be uniformly bounded to achieve synchronization of the error system. And a modal dependence criterion is obtained to ensure uniformly bounded and synchronous performance.

Description

Technical Field

[0001] The invention relates to a fault-tolerant synchronization control method, and in particular to a new synchronization criterion based on an aircraft engine control system. Background Art

[0002] Many dynamic models used for aircraft engine control systems are only established when the system state and known fault signals are known. In actual applications, the actual state of the system and the actual signal of the fault are unknown. In addition, the information interaction topology between the aircraft engine control system and its subsystems needs to change the interaction structure for self-repair under different fault conditions. Therefore, the discussion on the synchronization of switching aircraft engine control systems is crucial to ensure the stability of the system. Based on this idea, researchers have conducted a lot of research on the synchronization of switching aircraft engine control systems in continuous time and achieved a series of results. Summary of the invention

[0003] The purpose of the present invention is to propose a new criterion for an aircraft engine control system based on fault-tolerant synchronous control, which can effectively improve the performance of the aircraft engine control system.

[0004] The specific technical solution of the present invention is as follows: A new criterion for an aircraft engine control system based on fault-tolerant synchronous control comprises the following steps:

[0005] Under the interference of external noise, an aircraft engine control system model with unknown system state and fault signal is established, and its system output function is given

[0006] Based on the unknown system state and fault signal, a proportional integral intermediate observer is constructed to establish an estimated error system

[0007] By designing a segmented controller with estimated state and estimated fault, the controller acts on the continuous time and pulse time of the system respectively.

[0008] With the help of Lyapunov stability theorem and Young's inequality, the consistent final bounded criterion of modal dependence is obtained, and then the synchronization state is achieved.

[0009] For the aircraft engine control system in reference [1], the following dynamic model is established under the switching topology:

[0010]

[0011] In the formula, ζ(t), x p (t) represents the known and unknown system states, A, B, C, H, G represent the known parameter matrices, f(·) represents the activation function, u p (t) represents the control input, r p(t) represents unknown system failure, τ p (t) represents external input, Γ σ(t) denote the coupling strength, coupling matrix, and internal coupling matrix respectively. i , t i+1 ), based on σ(t) = ω, the system switching signal σ(t): [0, +∞) → Z is defined by ω, where It is the mode switching moment;

[0012] Definition p (t) = x p (t)-ζ(t), we can get the error system

[0013]

[0014] Where F(e p (t)) = f(x p (t))-f(ζ(t)).

[0015] In addition, its output system is given:

[0016] y p (t)=De p (t)

[0017] Where D is a known matrix;

[0018] With the help of Kronecker product, the system can be further written as:

[0019]

[0020] Due to x p (t) is an unknown state, then the error variable e p (t) is also unknown; To solve this problem, we consider a proportional integral intermediate observer; Next, an intermediate variable will be introduced;

[0021]

[0022] Where L R is the estimated gain.

[0023] So

[0024]

[0025] Based on the above formula, the proportional integral intermediate observer is designed as

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] make Then the estimated error system can be obtained

[0032]

[0033]

[0034]

[0035]

[0036] The pulse effect and switching behavior considered here do not occur simultaneously; and the pulse instant sequence t pj satisfy where t p and t pj denote the mode transition and the pulse instant, respectively; therefore, the control input u(t) is constructed as

[0037]

[0038] At this point, the error system can be rewritten as

[0039]

[0040] This control scheme can ensure that the system is uniformly bounded and stable. The proof process is as follows:

[0041] C001: For the pulse interval t∈[t p，j , t p，j+1 ),σ(t p )=ω, select the energy function of the following form:

[0042]

[0043] C002: In the formula, P 1 , P 2 , P 3 is any positive definite matrix;

[0044] C003: Calculate the first derivative of V(t), where:

[0045]

[0046] C004: Further, we can get:

[0047]

[0048] C005: Therefore

[0049] C006:

[0050]

[0051] C007: Based on Lyapunov stability theory, when have If [Ω] 5×5 <0, then the system is uniformly ultimately bounded.

[0052] C008: Therefore, the error variable e(t) can be estimated by a proportional-integral intermediate observer.

[0053] C009: For pulse instant t = t p，j+1 , can be obtained from C001.

[0054] C010:

[0055] C011: For the switching interval [t 0 , t 1 ), when t∈[t 0 , t 0，1 ), we can get

[0056] C012:

[0057] C013:

[0058] C014: Therefore, when t = t 0，1 Sometimes, there are

[0059] C015:

[0060] C016: When t∈[t 0，1 , t 0，2 ), we can get

[0061] C017:

[0062] C018:

[0063] C019: Therefore, when t = t 0，2 Sometimes, there are

[0064] C020:

[0065] C021: By analogy, we can get

[0066] C022:

[0067] C023: Therefore, when t = t 1 When , we can get:

[0068] C024:

[0069] C025: For the switching instant t = t 1 , there is a switching gain Make It is a modal dependency

[0070] C026: For the switching interval [t 1 , t 2 ), similar to C0011-C0025

[0071]

[0072] C027:

[0073]

[0074] C028: Next, V σ(t) The estimation of (t) is extended to the switching interval [t p , t p+1 )

[0075] C029:

[0076]

[0077] C030: According to the definition of mode-dependent average pulse interval,

[0078] C031:

[0079] C032: Therefore, there exists a positive constant M σ(t) satisfy So

[0080] C033:

[0081] C034: So

[0082]

[0083] C035:

[0084] C036: It should be pointed out that in the interval t∈[t p , t p+1 ), for σ(t)=ω, we have

[0085] C037:

[0086] C038: Therefore

[0087]

[0088] BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 A diagram of chaotic behavior for leaders;

[0090] Figure 2-6 It is the dynamic trajectory diagram of unknown error and tracking error;

[0091] Figure 7-9 Dynamic trajectory diagram for unknown fault signals and tracking fault signals;

[0092] Fig.10 This is the chaotic behavior diagram of the follower;

[0093] Fig.11 It is the dynamic trajectory diagram of the follower;

[0094] Fig.12 It is the dynamic trajectory diagram of the error between the leader and the follower; DETAILED DESCRIPTION

[0095] The present invention is further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0096] A new criterion for aircraft engine control system based on fault-tolerant synchronous control includes the following steps:

[0097] Step 1: Set various system parameters;

[0098] Step 2: construct intermediate variables according to unknown states and unknown fault signals;

[0099] Step 3: Set the proportional integral intermediate observer;

[0100] Step 4: Set up the estimation error system;

[0101] Step 5: Set the control input at the continuous moment and the pulse moment respectively;

[0102] Step 6: Verify whether the estimated error system is consistently ultimately bounded;

[0103] Step 7: Verify whether the error system is synchronized at the continuous moment, pulse moment, and switching moment.

[0104] An embodiment of the present invention is described below:

[0105] Consider a type of fault-tolerant synchronous control aircraft engine control system, and its corresponding dynamic models are:

[0106]

[0107]

[0108] f(x)=1.5tanh(x), α=0.4, σ(t)=1, 2, L R =[3.3645 3.5726 3.3645],L=[22.1041 173.4390 22.1041],L I =[3.5890 3.5890 3.5890]

[0109]

[0110]

[0111] The chaotic behavior of leaders Figure 1 As shown, the dynamic trajectory of the unknown error and tracking error under the proportional integral intermediate observer is as follows Figure 2-6 As shown in the figure, the dynamic trajectory of the unknown fault signal and the tracking fault signal under the proportional integral intermediate observer is as follows: Figure 7-9 As shown in Fig.10 As shown in the figure, the dynamic trajectory of the follower is as follows Fig.11 As shown in Figure 2, the dynamic trajectory of the error between the leader and the follower is as follows: Fig.12 Shown

[0112] References

[0113] [1] G. Zong, D. Yang, J. Lam, X. Song. Fault-Tolerant Control of Switched LPVSystems: A Bumpless Transfer Approach. IEEE / ASME Transactions on Mechatronics2022;27:1436-1446.

Claims

1. A control method for an aircraft engine system based on fault-tolerant synchronous control, characterized in that: The following steps are involved: Under the interference of external noise, the interactive topology and synchronous control method are used to establish an aircraft engine system model with unknown system states and fault signals, and the corresponding output function of the system is given. A proportional integral intermediate observer is designed, and the estimated error system is obtained using the Kronecker product technique. The principle of the constructed observer is to construct appropriate intermediate variables based on the unknown system state and unknown faults in the aircraft engine system. The actual value of the system state and the actual value of the intermediate variable are obtained by estimating the system state and the intermediate variable. Finally, the estimated value of the system fault is obtained by the actual value of the system state and the actual value of the intermediate variable. Based on the estimation of the actual state of the system and the actual fault signal in the proportional-integral intermediate observer, a segmented pulse controller is designed to act on the continuous time and pulse time of the system respectively. With the help of Lyapunov stability theorem and Young's inequality, the consistent final boundedness conditions of modal dependence are obtained to achieve the synchronization state.

2. The control method of an aircraft engine system based on fault-tolerant synchronous control according to claim 1, characterized in that Under external noise interference, the interactive topology and synchronous control method are used to establish an aircraft engine system model with unknown system states and fault signals. The specific steps are as follows: Under the interference of external noise, the model of aircraft engine control system with unknown system status and fault signals is as follows: Where f(x) = 1.5tanh(x), α = 0.4, L R =[3.3645 3.5726 3.3645], L=[22.1041 173.4390 22.1041],L I =[3.5890 3.5890 3.5890], Where ζ(t), x p (t) represents the known and unknown system states, A, B, C, H, G, D represent the known parameter matrices, f(·) represents the activation function, u p (t) represents the control input, r p (t) represents unknown system failure, τ p (t) represents external input, α>0, Γ σ(t) denote the coupling strength, coupling matrix, and internal coupling matrix respectively; for t∈[t i ,t i+1 ), based on σ(t) = ω, the system switching signal σ(t):[0,+∞)→Z is defined by ω, where It is the mode switching moment; Define the synchronization error as e p (t) = x p (t)-ζ(t), we can get the error system whereF(e p (t))=f(x p (t))-f(ζ(t)); In addition, its output system is given: and p (t)=Of p (t), Where D is a known matrix; With the help of Kronecker product, the system can be further written as Due to x p (t) is an unknown state, then the error variable e(t) is also unknown; to solve this problem, we consider a proportional integral intermediate observer; next, we will introduce an intermediate variable Where L R is the estimated gain; So Based on the above formula, the proportional integral intermediate observer is designed as make Then the estimated error system can be obtained The pulse effect and switching behavior considered here do not occur simultaneously; and the pulse instant sequence t pj satisfy where t p and t p,j denote the mode transition and impulse instant, respectively; Therefore, the control input u(t) is constructed as At this point, the error system can be rewritten as 3. According to the control method of the aircraft engine system based on fault-tolerant synchronous control according to claim 2, a control scheme is designed to ensure that the estimated error system is ultimately uniformly bounded. The proof process is as follows: B001: For the pulse interval t∈[t p,j ,t p,j+1 ),σ(t p )=ω, select the energy function of the following form: Where P1, P2, P3 are any positive definite matrices; B002: Calculate the first-order derivative of V(t): B003: Further, we can get: B004: Therefore in Oh 5,5 =-ρ 2 E B005: Based on Lyapunov stability theory, when have If [Ω] 5×5 <0, then the system is uniformly ultimately bounded; B006: Therefore, the error variable e(t) can be estimated by a proportional-integral intermediate observer; B007: For pulse instant t = t p,j+1 , from B001 we can get B008: For the switching interval [t0, t1), when t∈[t0, t 0,1 ), we can get Right now B0009: Therefore, when t=t 0，1 Sometimes, there are B0010: When t∈[t 0，1 ,t 0,2 ), we can get Right now B0011: Therefore, when t=t 0,2 Sometimes, there are B0012: By analogy, we can get B0013: Therefore, when t=t1, we can get: B0014: For the switching instant t=t1, there is a switching gain Make It is a modality-dependent approach; B0015: For the switching interval [t1, t2), similar to B0008-B0014, we can get Right now B0016: Next, V σ(t) The estimation of (t) is extended to the switching interval [t p ,t p+1 ) B0017: According to the definition of the modal-dependent average pulse interval, B0018: Therefore, there exists a positive constant M σ(t) satisfy So B0019: So in M=min{M σ(t) }; B0020: It should be pointed out that in the interval t∈[t p ,t p+1 ), for σ(t)=ω, we have B0021: Therefore

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