Closed-loop failure detection method for face-symmetrical rocket based on gap metric technique

Abstract

The application discloses a kind of face symmetry rocket closed-loop fault detection methods based on gap metric technology, belong to automatic control field.The method considers the complexity brought by system closed-loop control law, system model uncertainty disturbance in the whole fault detection process.First, in the first step of detection process, introduce coprime factorization method to obtain the left coprime factorization of the linearization model of system at state working point.Then, based on the left coprime factorization of system and gap metric, establish the closed-loop fault detection model of face symmetry rocket servo mechanism, generate the fault detection signal on three channels.Moreover, based on the left coprime factorization of system and control law, obtain the threshold of fault detection signal on three channels, which considers the influence brought by system closed-loop control law.The application can better handle the problem that closed-loop control law masks fault signal, thereby improving the accuracy of fault detection system.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology, and in particular to a method for detecting closed-loop faults in symmetrical rockets based on gap measurement technology. Background Technology

[0002] A symmetrical launch vehicle is a rocket that exhibits symmetry in a specific plane or direction, differing in design from traditional axisymmetric rockets. The unique structural layout of symmetrical rockets allows them to flexibly adapt to diverse mission requirements, such as uneven payload distribution or the carrying of multiple functional modules. However, the not entirely symmetrical design also makes the rocket more susceptible to aerodynamic disturbances during flight, increasing the complexity of attitude control and the likelihood of malfunctions. The actuators of symmetrical launch vehicles utilize six engines (core stage and booster stages) that oscillate bidirectionally to provide three-channel control torque. The unique structural characteristics of symmetrical rockets place higher demands on actuator fault detection and fault-tolerant control. Therefore, how to efficiently detect faults in the actuators of symmetrical rockets and ensure their reliable operation through fault-tolerant control mechanisms is a key issue in current research.

[0003] Currently, there are some research results on fault detection technology for closed-loop control systems. In reality, most control systems are closed-loop control systems. Fault detection is often difficult if the control law is not considered. However, the above-mentioned method has not yet been applied to the detection of servo faults in symmetrical rockets. Moreover, the attitude control system of symmetrical rockets is a closed-loop control system, and the existing fault detection methods have not considered the detection method based on coprime decomposition and gap measurement technology. Summary of the Invention

[0004] This invention provides a closed-loop fault detection method for symmetrical rockets based on gap measurement technology, which takes into account the influence of the closed-loop control law on fault detection and can realize three-channel fault detection of symmetrical rockets under closed-loop control.

[0005] This invention provides a closed-loop fault detection method for a symmetrical rocket based on gap measurement technology, comprising the following steps:

[0006] Step 1: Based on the characteristics of the bundled launch vehicle using the combined swaying of the core stage and booster engines for attitude control, establish a kinematic and dynamic model of the ascent phase of the symmetrical rocket.

[0007] Step 2: Based on the kinematic and dynamic model of the ascent phase of the symmetrical rocket, the swing angle control commands between the core stage and the booster are proportionally distributed according to their respective maximum swing angle limits.

[0008] Step 3: Based on the control allocation relationship of the swing angle control command between the core stage and the booster, the kinematic and dynamic model of the ascent stage of the symmetrical rocket is converted into a symmetrical rocket input-output model with the input being the three-channel control swing angle command and the output being the attitude angle of the symmetrical rocket.

[0009] Step 4: Perform operating point linearization on the state operating point of the symmetrical rocket input-output model to obtain the linearized model at the state operating point.

[0010] Step 5: Considering the system model uncertainty of the symmetrical rocket after linearization at the operating point, perform coprime decomposition on the linearized model to obtain the left coprime decomposition of the nominal model.

[0011] Step 6: Based on the left coprime decomposition of the nominal model and the gap measurement technology, establish a closed-loop fault detection system model for the symmetric rocket for servo mechanism faults, and obtain the fault detection signals on the three channels.

[0012] Step 7: For the fault detection signals on the three channels, determine the fault detection signal thresholds on the three channels in the symmetrical rocket closed-loop fault detection system model based on the left coprime decomposition and closed-loop control law, and determine whether the actuator on the channel has failed based on the fault detection signals and the fault detection signal thresholds.

[0013] Optionally, in one embodiment of the present invention, in step 1, the kinematic and dynamic model of the ascent phase of the symmetrical rocket is as follows:

[0014]

[0015] in, These represent the state variables, namely the rocket's pitch angle, yaw angle, roll angle, pitch rate, yaw rate, and roll rate. Indicates system output; The combined swing angle, equivalent to that of the three-channel upper core stage and booster, represents the system input; d1,d 3xj ,d 3zt The system parameters are defined in a symmetrical rocket system model before the state and control variables. d3″ xj ,d3″ zt The system parameters before the second derivative of the control variables in the face-symmetric rocket system model; α, α w ,β,β w These are respectively: angle of attack, additional angle of attack, sideslip angle, and additional sideslip angle; The points on the state and control parameters represent the first and second derivatives, respectively.

[0016] Optionally, in one embodiment of the present invention, in step 2, the swing angle control command between the core stage and the booster is:

[0017]

[0018] k1 = k2 = 0.5

[0019] in, These represent the core-level yaw control commands for pitch, yaw, and roll channels, respectively. These represent the control commands for pitch, yaw, and roll channel booster yaw angle, respectively. These represent the pitch, yaw, and roll channel basic controller outputs, respectively, with k1 and k2 being the core stage and booster pitch angle allocation coefficients, respectively.

[0020] Optionally, in one embodiment of the present invention, in step 3, the input-output model of the symmetrical rocket is:

[0021]

[0022] The nonlinear system representation of the symmetrical rocket input-output model is as follows:

[0023] x = f(x, u, t)

[0024] y = g(x, u, t)

[0025] in, It is the equivalent combined swing angle obtained from the control allocation relationship on the three channels, representing the system input.

[0026] Optionally, in one embodiment of the present invention, in step 4, the state-space model described by A, B, C, and D is used as the linearized model of the symmetrical rocket input-output model at the operating point of the state:

[0027]

[0028] Δy=CΔx+DΔu

[0029]

[0030] Where x0 and u0 are the state operating points of the symmetrical rocket input-output model, Δx = x - x0, Δy = y - x0, and Δu = u - u0.

[0031] Optionally, in one embodiment of the present invention, in step 5, considering the system model uncertainty existing after linearization of the symmetrical rocket at the operating point, the linearized model is coprime decomposed to obtain the left coprime decomposition of the nominal model as follows:

[0032] G0(s)=Ml0(s) -1 Nl0(s)

[0033]

[0034] Ml(s)=(A Ml B Ml C Ml D Ml )

[0035] Nl(s)=(A Nl B Nl C Nl D Nl )

[0036] Wherein, Ml(s) -1 Nl(s) is the left coprime decomposition of the nominal model G(s), satisfying Ml(s)Ml -1 (s)+Nl(s)Nl -1 (s) = I, where I is the unit transfer function matrix, Ml0(s) -1 Nl0(s) is the left coprime decomposition of the linearized model G0(s), satisfying Ml0(s)Ml0 -1 (s)+Nl0(s)Nl0 -1 (s) = I, and The parameters that describe the uncertainty of the system model, (A) Ml B Ml C Ml D Ml ) is the state-space model of the left coprime submodel Ml(s), (A Nl B Nl C Nl D Nl ) is the state-space model of the left coprime decomposition submodel Nl(s).

[0037] Optionally, in one embodiment of the present invention, in step 6, the fault detection signal on the three channels is:

[0038]

[0039] Optionally, in one embodiment of the present invention, in step 7, the fault detection signal threshold on the three channels is J. th :

[0040]

[0041] Where K is the transfer function represented by the system control law, G is the nominal model, J(K,G) is the transfer function matrix with respect to G and K, and v is the system closed-loop control command. Used to describe the uncertainty of the system model, δ Δ To describe the uncertainty parameters of the system model, || || ∞ Represents the infinite norm, It is a 2-norm.

[0042] This invention discloses a closed-loop fault detection method for symmetrical rockets based on gap metric technology. The method generates a fault detection signal using coprime decomposition and gap metric techniques. This fault detection signal represents the distance between the nominal system and the faulty system of the symmetrical rocket, enabling effective detection of early-stage or minor faults. The invention generates a fault detection signal threshold based on coprime decomposition and gap metric techniques. This threshold considers the uncertainty of the system model and the closed-loop control law, effectively addressing the problem of the closed-loop system control law masking the fault signal.

[0043] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0044] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0045] Figure 1 A flowchart of a closed-loop fault detection method for a symmetrical rocket based on gap measurement technology according to an embodiment of the present invention;

[0046] Figure 2 This is a framework diagram of a symmetrical rocket closed-loop fault detection method based on gap measurement technology according to an embodiment of the present invention.

[0047] Figure 3 This is a graph showing the command values ​​and actual output values ​​of the control system in an embodiment of the present invention when the No. 1 servo at the core level experiences a jamming fault.

[0048] Figure 4 This is a diagram showing the fault signal detection values ​​and threshold values ​​of the three channels of the control system in an embodiment of the present invention under conditions of no jamming fault.

[0049] Figure 5 This is a diagram showing the fault signal detection values ​​and thresholds of the control system in an embodiment of the present invention when the No. 1 servo in the core stage experiences a stuck fault. Detailed Implementation

[0050] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0051] like Figure 1 and Figure 2 As shown, the method for detecting closed-loop faults in a symmetrical rocket based on gap measurement technology includes the following steps:

[0052] Step 1: Based on the characteristics of the bundled launch vehicle using the combined oscillation of the core stage and booster engine for attitude control, establish a kinematic and dynamic model of the ascent phase of the symmetrical rocket.

[0053] Optionally, in one embodiment of the present invention, in step 1, the kinematic and dynamic model of the ascent phase of the symmetrical rocket is as follows:

[0054]

[0055] in, These represent the state variables, namely the rocket's pitch angle, yaw angle, roll angle, pitch rate, yaw rate, and roll rate. Indicates system output; The combined swing angle, equivalent to that of the three-channel upper core stage and booster, represents the system input; d1,d 3xj ,d 3zt The system parameters are defined in a symmetrical rocket system model before the state and control variables. d3″ xj ,d3″ zt The system parameters before the second derivative of the control variables in the face-symmetric rocket system model; α, α w ,β,β w These are respectively: angle of attack, additional angle of attack, sideslip angle, and additional sideslip angle; The points on the state and control parameters represent the first and second derivatives, respectively.

[0056] The servo mechanism is limited by a single unit of 6°, a speed of 10° / s, and an acceleration of 10 rad / s. The actuator transfer function is based on the standard second-order transfer function, and its natural frequency and damping ratio are [32 0.3].

[0057] Step 2: Based on the kinematic and dynamic model of the ascent phase of the symmetrical rocket, the swing angle control commands between the core stage and the booster are proportionally distributed according to their respective maximum swing angle limits.

[0058] Optionally, in one embodiment of the present invention, in step 2, the swing angle control command between the core stage and the booster is:

[0059]

[0060] k1 = k2 = 0.5

[0061] in, These represent the core-level yaw control commands for pitch, yaw, and roll channels, respectively. These represent the control commands for pitch, yaw, and roll channel booster yaw angle, respectively. These represent the pitch, yaw, and roll channel basic controller outputs, respectively, with k1 and k2 being the core stage and booster pitch angle allocation coefficients, respectively.

[0062] Step 3: Based on the control allocation relationship between the core stage and the booster, the kinematic and dynamic model of the ascent phase of the symmetrical rocket is converted into a symmetrical rocket input-output model with the input being the three-channel control angle command and the output being the attitude angle of the symmetrical rocket.

[0063] Optionally, in one embodiment of the present invention, in step 3, the input-output model of the symmetrical rocket is:

[0064]

[0065] The nonlinear system representation of the symmetrical rocket input-output model is as follows:

[0066] x = f(x, u, t)

[0067] y = g(x, u, t)

[0068] in, It is the equivalent combined swing angle obtained from the control allocation relationship on the three channels, representing the system input.

[0069] Step 4: Perform operating point linearization on the state operating point of the symmetrical rocket input-output model to obtain the linearized model at the state operating point.

[0070] Optionally, in one embodiment of the present invention, in step 4, the state-space model described by A, B, C, and D is used as the linearized model G0(s) of the symmetric rocket input-output model at the state operating point:

[0071]

[0072] Δy=CΔx+DΔu

[0073]

[0074] Where, x0 = [1.51350.05860.0509000] T And u0 = [-0.01660.01660.0144] T For the state operating point of the symmetric rocket input-output model, Δx = x - x0, Δy = y - x0, Δu = u - u0.

[0075] Step 5: Considering the system model uncertainty of the face-symmetric rocket after linearization at the operating point, perform coprime decomposition on the linearized model to obtain the left coprime decomposition of the nominal model.

[0076] In the embodiments of this application, the system refers to the system of a symmetrical rocket after linearization at the operating point, which has uncertainties.

[0077] Optionally, in one embodiment of the present invention, in step 5, considering the system model uncertainty existing after linearization of the symmetrical rocket at the operating point, the linearized model is coprime decomposed to obtain the left coprime decomposition of the nominal model as follows:

[0078] G0(s)=Ml0(s) -1 Nl0(s)

[0079]

[0080] Ml(s)=(A Ml B Ml C Ml D Ml )

[0081] Nl(s)=(A Nl B Nl C Nl D Nl )

[0082] Wherein, Ml(s) -1 Nl(s) is the left coprime decomposition of the nominal model G(s), satisfying Ml(s)Ml -1 (s)+Nl(s)Nl -1 (s) = I, where I is the unit transfer function matrix, Ml0(s) -1 Nl0(s) is the left coprime decomposition of the linearized model G0(s), satisfying Ml0(s)Ml0 -1 (s)+Nl0(s)Nl0 -1 (s) = I, and The parameters that describe the uncertainty of the system model, (A) Ml B Ml C Ml DMl ) is the state-space model of the left coprime submodel Ml(s), (A Nl B Nl C Nl D Nl ) is the state-space model of the left coprime decomposition submodel Nl(s).

[0083] Step 6: Based on the left coprime decomposition of the nominal model and the gap measurement technique, establish a closed-loop fault detection system model for the symmetric rocket for servo mechanism faults, and obtain the fault detection signals on the three channels.

[0084] Optionally, in one embodiment of the present invention, in step 6, the fault detection signal on the three channels is:

[0085]

[0086] Step 7: For the fault detection signals on the three channels, determine the fault detection signal thresholds on the three channels in the symmetrical rocket closed-loop fault detection system model based on the left coprime decomposition and closed-loop control law. Determine whether the actuators on the channels have failed based on the fault detection signals and the fault detection signal thresholds.

[0087] The present invention first obtains the left coprime decomposition of the linearized model at the operating point, and then establishes a closed-loop fault detection system model for a symmetrical rocket based on the left coprime decomposition and gap measurement technology. The fault detection signal threshold is obtained based on the left coprime decomposition and the closed-loop control law. When a fault occurs in the system actuator, the fault detection signal exceeds the threshold, and the fault of the actuator on that channel is detected.

[0088] Optionally, in one embodiment of the present invention, in step 7, the fault detection signal threshold on the three channels is J. th :

[0089]

[0090] Where K is the transfer function represented by the system control law, G is the nominal model, J(K,G) is the transfer function matrix with respect to G and K, and v is the system closed-loop control command. Used to describe the uncertainty of the system model, δ Δ To describe the uncertainty parameters of the system model, || || ∞ Represents the infinite norm, It is a 2-norm.

[0091] The effectiveness of the present invention is verified by simulation using the accompanying drawings and specific embodiments. The simulation parameters are as follows:

[0092] Parameters of a symmetrical rocket model:

[0093] Initial state value: x0 = [1.51350.05860.0509000] T u0 = [-0.01660.01660.0144] T The controller gain is: (All three channels are identical), the reference signal is v = [1.570700]. T .

[0094] Consider a potential servo mechanism jamming failure model.

[0095] Fault 1: The core-level servo experiences a jamming fault at t=40s, and the jamming angle is -2°.

[0096]

[0097] in, This is the command value for the first servo mechanism at the core level. This is the actual value for the No. 1 servo mechanism at the core level.

[0098] Determine the threshold: Based on the calculation formula, select the parameter δ to describe the uncertainty of the system model. Δ =0.05, J can be calculated. th = [0.0033 0.0266 0.0042].

[0099] Fault such as being stuck Figure 3 As shown, the symmetrical rocket experienced a jamming fault in its core stage 1 servo at 40 seconds, with a jamming angle of -2°.

[0100] The fault signal detection diagram under fault-free conditions is as follows: Figure 4 As shown, in the absence of a jamming fault, the detection values ​​of the three-channel fault signals did not exceed the threshold.

[0101] The fault signal detection diagram under fault conditions is as follows: Figure 5 As shown in the figure, the symmetrical rocket experienced a jamming fault in core stage 1 servo at 40 seconds. According to the servo synthesis relationship, core stage 1 servo affects the pitch and roll channels, but not the yaw channel. The simulation results show that the fault detection signal values ​​in the pitch and roll channels exceeded the threshold, indicating a servo fault in that channel. The simulation results verify the effectiveness of the proposed fault detection strategy.

[0102] This invention presents a closed-loop fault detection method for symmetrical rockets based on gap metric technology. For a six-degree-of-freedom model of a symmetrical rocket, it proposes a method based on closed-loop fault detection technology to achieve three-channel fault detection, taking into account the system's closed-loop control law. Throughout the fault detection process, the complexity caused by the system's closed-loop control law and uncertainties in the system model is considered. First, in the first step of the detection process, a coprime decomposition method is introduced to obtain the left coprime decomposition of the linearized model of the system at the operating point. Next, based on the system's left coprime decomposition and gap metric, a closed-loop fault detection model for the symmetrical rocket servo mechanism is established, generating fault detection signals on the three channels. Furthermore, based on the system's left coprime decomposition and control law, a threshold for the fault detection signals on the three channels is obtained, which takes into account the influence of the system's closed-loop control law. Finally, for jamming faults in the symmetrical rocket servo mechanism, this invention effectively addresses the problem of fault signal masking caused by the closed-loop control law, thereby improving the accuracy of the fault detection system.

[0103] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0104] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0105] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

Claims

1. A closed-loop fault detection method for surface-symmetric rockets based on gap measurement technology, characterized in that, Includes the following steps: Step 1: Based on the characteristics of the bundled launch vehicle using the combined swaying of the core stage and booster engines for attitude control, establish a kinematic and dynamic model of the ascent phase of the symmetrical rocket. Step 2: Based on the kinematic and dynamic model of the ascent phase of the symmetrical rocket, the swing angle control commands between the core stage and the booster are proportionally distributed according to their respective maximum swing angle limits. Step 3: Based on the control allocation relationship of the swing angle control command between the core stage and the booster, the kinematic and dynamic model of the ascent stage of the symmetrical rocket is converted into a symmetrical rocket input-output model with the input being the three-channel control swing angle command and the output being the attitude angle of the symmetrical rocket. Step 4: Perform operating point linearization on the state operating point of the symmetrical rocket input-output model to obtain the linearized model at the state operating point. Step 5: Considering the system model uncertainty after linearizing the symmetrical rocket at the operating point, perform coprime decomposition on the linearized model to obtain the left coprime decomposition of the nominal model; in Step 5, considering the system model uncertainty after linearizing the symmetrical rocket at the operating point, perform coprime decomposition on the linearized model to obtain the left coprime decomposition of the nominal model as follows: in, For nominal model Left coprime decomposition, satisfying , For the unit transfer function matrix, For linearized models Left coprime decomposition, satisfying , and Parameters that describe the uncertainty of the system model. Left coprime decomposition model State-space model, Left coprime decomposition model State-space model; Step 6: Based on the left coprime decomposition of the nominal model and the gap measurement technology, establish a closed-loop fault detection system model for the symmetric rocket for servo mechanism faults, and obtain the fault detection signals on the three channels. Step 7: For the fault detection signals on the three channels, determine the fault detection signal thresholds on the three channels in the symmetrical rocket closed-loop fault detection system model based on the left coprime decomposition and closed-loop control law, and determine whether the actuator on the channel has failed based on the fault detection signals and the fault detection signal thresholds.

2. The method according to claim 1, characterized in that, In step 1, the kinematic and dynamic model of the ascent phase of the symmetrical rocket is as follows: in, These represent the state variables, namely the rocket's pitch angle, yaw angle, roll angle, pitch rate, yaw rate, and roll rate. Indicates system output; The combined swing angle, equivalent to that of the three-channel upper core stage and booster, represents the system input; The system parameters are defined in a symmetrical rocket system model before the state and control variables. The system parameters before the second derivative of the control variables in the symmetric rocket system model; These are respectively: angle of attack, additional angle of attack, sideslip angle, and additional sideslip angle; The points on the state and control parameters represent the first and second derivatives, respectively.

3. The method according to claim 2, characterized in that, In step 2, the yaw angle control command between the core stage and the booster is: in, , , These represent the core-level yaw control commands for pitch, yaw, and roll channels, respectively. , , These represent the control commands for pitch, yaw, and roll channel booster yaw angle, respectively. , , These represent the pitch, yaw, and roll channel basic controller outputs of the yaw angle commands, respectively. These are the core stage and booster swing angle allocation coefficients, respectively.

4. The method according to claim 2, characterized in that, In step 3, the input-output model of the symmetrical rocket is as follows: The nonlinear system representation of the symmetrical rocket input-output model is as follows: in, It is the equivalent combined swing angle obtained from the control allocation relationship on the three channels, representing the system input.

5. The method according to claim 4, characterized in that, In step 4, with The described state-space model, as a linearized model of the input-output model of the symmetric rocket at the operating point, is as follows: in, and This represents the operating state of the symmetrical rocket input-output model. .

6. The method according to claim 5, characterized in that, In step 6, the fault detection signal on the three channels is: 。 7. The method according to claim 6, characterized in that, In step 7, the fault detection signal threshold on the three channels is: : in, Let be the transfer function represented by the system's control law. For the nominal model, Let G be the transfer function matrix with respect to K. This refers to the closed-loop control command for the system. , Used to describe the uncertainty of system models To describe the uncertainty parameters of the system model, Represents the infinite norm, It is a 2-norm.

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