Aircraft flight controller reconstruction method based on fault detection

Abstract

The invention belongs to the field of aircraft fault-tolerant control, and particularly relates to an aircraft flight controller reconstruction method based on fault detection, and the method comprises the steps: transmitting fault information to a controller when a fault occurs in an aircraft training process; the controller obtains the disturbance quantity brought by the aircraft system, control reconstruction of the controller is carried out by using a self-adaptive sliding mode method, and a self-adaptive sliding mode control law after reconstruction is completed is obtained; and the self-adaptive sliding mode control law is sent to an actuator, and fault-tolerant control under the aircraft fault state is carried out. A system fault is detected through an external safety device, and then a controller is reconstructed by using a self-adaptive sliding mode method, so that the fault of an aircraft in a landing process can be detected in time, and safe landing of the aircraft in a fault mode is realized. An external safety device is adopted, so that an existing aircraft system does not need to be greatly changed; and due to the adoption of the self-adaptive law, the device can realize real-time fault detection and controller reconstruction.

Description

Technical Field

[0001] The present application belongs to the field of aircraft fault-tolerant control, and in particular relates to a method for reconfiguring an aircraft flight controller based on fault detection. Background Art

[0002] The time from entering the glide path to landing successfully is very short, and the glide path control is very demanding. However, some objective uncertainties such as airflow and sea surface conditions, and subjective uncertainties such as aircraft landing guidance and aircraft control, may lead to improper track control and failure to land at the scheduled landing point, which may directly lead to landing failure and even cause serious accidents. At the same time, the aircraft system is complex and is prone to failures due to environmental factors during training, such as sensor failure, control surface failure, engine failure, fuselage structure failure, etc. As long as the aircraft does not lose the necessary lift and flight maneuverability, and cooperates with guidance and flight control, the flight performance of the malfunctioning aircraft can be restored to a certain extent.

[0003] Therefore, it is very important to study the problem of aircraft fault detection and controller reconstruction after failure. Summary of the invention

[0004] The purpose of this application is to provide an aircraft flight controller reconstruction method based on fault detection to solve the problem that improper landing control of existing aircraft easily leads to landing failure.

[0005] The technical solution of the present application is: a method for reconfiguring an aircraft flight controller based on fault detection, comprising: After the aircraft enters the landing phase, the evaluation system updates the physical parameters of the aircraft in real time, and the external safety device starts fault detection. If a fault occurs during the aircraft training, the fault information is sent to the controller. The controller obtains the disturbance caused by the aircraft system, uses the adaptive sliding mode method to reconstruct the control of the controller, and obtains the reconstructed adaptive sliding mode control law; The adaptive sliding mode control law is sent to the actuator to perform fault-tolerant control under aircraft fault conditions.

[0006] Preferably, the adaptive sliding mode control law is specifically designed as follows: Assume that the disturbance caused by the fault to the aircraft system is , based on the assumed disturbance Establish aircraft fault modal dynamic equations; The error is obtained according to the aircraft fault modal dynamic equation , based on the error Create sliding surface ; According to the sliding surface A Lyapunov candidate function is established, and then the controller is reconstructed by adding disturbance estimation error to the Lyapunov candidate function to obtain the reconstructed adaptive sliding mode control law.

[0007] Preferably, the aircraft fault modal dynamic equation is: ; in, is the state matrix, for The derivative of is the control matrix, is the system matrix, is the input matrix, Represents the amount of disturbance caused by aircraft failure.

[0008] Preferably, the error is , the sliding surface is ; In the formula, is the sliding mode controller gain, For time, is the expected state quantity.

[0009] Preferably, the specific process of reconstructing the controller is: Lyapunov candidate function for: ; In the formula, for The transpose of For Lyapunov candidate function Taking the derivative we get: ; In the formula, for The derivative of for The derivative of for The derivative of make is negative, for Lyapunov candidate function The derivative of is transformed to get: ; In the formula, is the constant coefficient to be determined, To deal with fault disturbance The estimator of is a time-invariant disturbance; Assumptions , represents the disturbance estimation error; Then we get the Lyapunov candidate function with added perturbation estimation error: : ; in, is the constant coefficient to be determined; Lyapunov candidate function for the error in estimating the added perturbation The derivative is: ; In the formula, for The derivative of make is negative, and we get the adaptive law for: ; The adaptive law Substitute controller The expression of the reconstructed controller is: ; The reconstructed controller expression is the reconstructed adaptive sliding mode control law.

[0010] Preferably, the specific method for performing fault detection is: The external safety device directly extracts the raw data after external sensor fusion through sensor wiring; In the decision system of the external safety device, the measured value of the raw data is compared with the measured value of the internal sensor to obtain the measurement error; Set an error threshold and compare the measured error with the error threshold to determine whether a fault has occurred; if the error threshold is exceeded, it is determined that a fault has occurred during aircraft training.

[0011] The aircraft flight controller reconstruction method based on fault detection of the present application detects system faults through an external safety device, and then uses an adaptive sliding mode method to reconstruct the controller, so that the faults of the aircraft during landing can be detected in time, and a safe landing under the aircraft fault mode can be achieved. The use of an external safety device does not require much change to the existing aircraft system; and because of the use of an adaptive law, the device can achieve real-time fault detection and controller reconstruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0013] Figure 1 This is a schematic diagram of the overall process of this application. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] A method for reconfiguring an aircraft flight controller based on fault detection detects system faults through an external safety device, and then uses an adaptive sliding mode method to reconstruct the controller, so that faults of the aircraft during landing can be detected in time, achieving safe landing under the aircraft fault mode.

[0016] like Figure 1 As shown, the following steps are included: Step S100, after the aircraft enters the landing phase, the evaluation system updates the physical parameters of the aircraft in real time, and the external safety device starts fault detection; when it is determined that a fault occurs during the aircraft training process, the fault information is sent to the controller.

[0017] Preferably, the specific method for performing fault detection is: The external safety device directly extracts the raw data after external sensor fusion through external sensor wiring for reference state estimation; In the decision system of the external safety device, the measured value of the raw data is compared with the measured value of the internal sensor to obtain the measurement error; The measurement error between the integrated measurement value and the measurement value of the internal sensor within a fixed time window is set, and the error threshold is set. The measurement error is compared with the error threshold to determine whether a fault occurs; if the error threshold is exceeded, it is determined that a fault has occurred during the aircraft training process.

[0018] Step S200, the controller obtains the disturbance caused by the aircraft system, uses the adaptive sliding mode method to reconstruct the control of the controller, and obtains a reconstructed adaptive sliding mode control law; Preferably, the adaptive sliding mode control law is specifically designed as follows: Step S210, assuming that the disturbance caused by the fault to the aircraft system is , based on the assumed disturbance The aircraft fault modal dynamic equation is established as follows: ; in is the state matrix, for The derivative of is the control matrix, is the system matrix, is the input matrix, Represents the disturbance caused by the aircraft failure, which has a time-invariant nature.

[0019] Step S220, obtaining the error according to the aircraft fault modal dynamic equation , based on the error Create sliding surface .

[0020] Preferably, the error is , the sliding surface is ; In the formula, is the sliding mode controller gain, For time, is the expected state quantity.

[0021] Step S230, according to the sliding surface A Lyapunov candidate function is established, and then the controller is reconstructed by adding disturbance estimation error to the Lyapunov candidate function.

[0022] Preferably, the specific process of reconstructing the controller is: Lyapunov candidate function for: ; In the formula, for The transpose of .

[0023] For Lyapunov candidate function Taking the derivative we get: ; In the formula, for The derivative of for The derivative of for The derivative of .

[0024] make is negative, for Lyapunov candidate function The derivative of is transformed to get: ; In the formula, is the constant coefficient to be determined, To deal with fault disturbance The estimator of is a time-invariant disturbance.

[0025] Assumptions , represents the disturbance estimation error; Then we get the Lyapunov candidate function with added perturbation estimation error: :

[0026] in, is the constant coefficient to be determined.

[0027] Lyapunov candidate function for the error in estimating the added perturbation The derivative is: ; In the formula, for The derivative of .

[0028] make If is negative, we can get the adaptive law for: ; The adaptive law Substitute controller In the above example, we can get the expression of the reconstructed controller as: ; The reconstructed controller expression is the reconstructed adaptive sliding mode control law.

[0029] Step S300, sending the above-mentioned adaptive sliding mode control law to the actuator through the decision system to perform fault-tolerant control under the aircraft fault state.

[0030] In summary, the present application detects system failures through an external safety device, and then uses an adaptive sliding mode method to reconstruct the controller, so that the failure of the aircraft during landing can be detected in time, and a safe landing under the aircraft failure mode is achieved. The use of an external safety device does not require much change to the existing aircraft system; and because of the use of an adaptive law, the device can achieve real-time fault detection and controller reconstruction.

[0031] Finally, it should be noted that: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other; Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for reconfiguring an aircraft flight controller based on fault detection, characterized in that: include: When the aircraft enters the landing phase, the evaluation system updates the physical parameters of the aircraft in real time, and the external safety device starts fault detection; When it is determined that a fault occurs during aircraft training, the fault information is sent to the controller; The controller obtains the disturbance caused by the aircraft system, uses the adaptive sliding mode method to reconstruct the control of the controller, and obtains the reconstructed adaptive sliding mode control law; The adaptive sliding mode control law is sent to the actuator to perform fault-tolerant control under aircraft fault conditions.

2. The aircraft flight controller reconstruction method based on fault detection as claimed in claim 1, characterized in that: The adaptive sliding mode control law is specifically designed as follows: Assume that the disturbance caused by the fault to the aircraft system is , based on the assumed disturbance Establish aircraft fault modal dynamic equations; The error is obtained according to the aircraft fault modal dynamic equation , based on the error Create sliding surface ; According to the sliding surface A Lyapunov candidate function is established, and then the controller is reconstructed by adding disturbance estimation error to the Lyapunov candidate function to obtain the reconstructed adaptive sliding mode control law.

3. The aircraft flight controller reconstruction method based on fault detection as claimed in claim 2, characterized in that: The aircraft fault modal dynamic equation is: ； in, is the state matrix, for The derivative of is the control matrix, is the system matrix, is the input matrix, Represents the disturbance amount caused by aircraft failure.

4. The aircraft flight controller reconstruction method based on fault detection as claimed in claim 3, characterized in that: The error is , the sliding surface is ; In the formula, is the sliding mode controller gain, For time, is the expected state quantity.

5. The aircraft flight controller reconstruction method based on fault detection as claimed in claim 4, characterized in that: The specific process of reconstructing the controller is as follows: Lyapunov candidate function for: ； In the formula, for The transpose of For Lyapunov candidate function Taking the derivative we get: ； In the formula, for The derivative of for The derivative of for The derivative of make is negative, for Lyapunov candidate function The derivative of is transformed to get: ； In the formula, is the constant coefficient to be determined, To deal with fault disturbance The estimator of is a time-invariant disturbance; Assumptions , represents the disturbance estimation error; Then we get the Lyapunov candidate function with added perturbation estimation error: : ； in, is the constant coefficient to be determined; Lyapunov candidate function for the error in estimating the added perturbation The derivative is: ； In the formula, for The derivative of make is negative, and we get the adaptive law for: ； The adaptive law Substitute controller The expression of the reconstructed controller is: ； The reconstructed controller expression is the reconstructed adaptive sliding mode control law.

6. The aircraft flight controller reconstruction method based on fault detection as claimed in claim 1, characterized in that: The specific method for fault detection is: The external safety device directly extracts the raw data after external sensor fusion through sensor wiring; In the decision system of the external safety device, the measured value of the raw data is compared with the measured value of the internal sensor to obtain the measurement error; Set an error threshold, compare the measurement error with the error threshold, and determine whether a fault occurs; If the error threshold is exceeded, it is determined that a failure has occurred during aircraft training.

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