Device and Method for Diagnosing and Predicting Aircraft Electrical Circuit Faults

Abstract

An embodiment of the present invention discloses a device and method for diagnosing and predicting aircraft electrical circuit faults. The device includes a remote power controller RPC control engine based on a digital signal processor and a power line interface module. The power line interface module transmits the excitation signal generated by the RPC control engine and sends it to the aircraft electrical circuit. The response signal generated when the aircraft electrical circuit is excited is transmitted to the RPC control engine through the power line interface module. The RPC control engine is used to realize the diagnosis and prediction of aircraft electrical circuit faults. This application does not require a large number of sensors to be set up, nor does it require the transmission, collection, and processing of a large amount of data from these sensors, making the diagnosis and prediction of aircraft electrical circuit faults more reliable, economical, and practical.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft fault detection, and particularly to a device and method for diagnosing and predicting faults in aircraft electrical circuits. Background Art

[0002] The safety of aircraft electrical circuits has always received extensive attention. Aging of insulating materials, improper installation and operation, mechanical vibration, etc. can all cause faults in aircraft electrical circuits. Therefore, diagnosing and predicting these faults is very necessary and important. In the prior art, the method of adding sensors is adopted to diagnose faults. For example, a "flexible sensor" embedded in a wiring clip is used to capture "partial discharge" to locate the faulty cable. However, since a large number of cables are used in the aircraft power system, a large number of sensors need to be added, and at the same time, a large amount of data from these sensors needs to be transmitted, collected, and processed. This makes it easy to have problems such as deviation, waste, and low feasibility in the actual implementation of the above method. Moreover, the above method only realizes the diagnosis of faults and does not mention the prediction of faults.

[0003] Therefore, it has become an urgent problem to propose a reliable, economical, and practical method for diagnosing and predicting faults in aircraft electrical circuits. Summary of the Invention

[0004] In view of this, the present application proposes a device and method for diagnosing and predicting faults in aircraft electrical circuits.

[0005] In a first aspect, the present invention provides a device for diagnosing and predicting faults in aircraft electrical circuits, and the diagnosing and predicting device includes:

[0006] A power line interface module, a remote power controller RPC control engine based on a digital signal processor;

[0007] One end of the power line interface module is connected to a feeder line, and the other end of the power line interface module is connected to one end of the RPC control engine;

[0008] The RPC control engine is used to generate an excitation signal and send the excitation signal to the power line interface module;

[0009] The power line interface module is used to couple the excitation signal to the feeder line and transmit it to the aircraft electrical circuit. When the aircraft electrical circuit is excited by the excitation signal, a response signal is generated;

[0010] The power line interface module is further used to receive the response signal and send it to the RPC control engine;

[0011] The RPC control engine is further used to diagnose and predict the line fault of the aircraft electrical circuit according to the response signal.

[0012] Optionally, the diagnosis and prediction device further includes a voltage sensor and a current sensor, which are arranged on the feeder line, and one ends of the voltage sensor and the current sensor are respectively connected to the RPC control engine;

[0013] The voltage sensor is used to detect the voltage value when the aircraft electrical circuit is excited by the excitation signal, and transmit the voltage value to the RPC control engine;

[0014] The current sensor is used to detect the current value when the aircraft electrical circuit is excited by the excitation signal, and transmit the current value to the RPC control engine.

[0015] Optionally, the aircraft electrical circuit further includes a main power switch, specifically including:

[0016] The main power switch is arranged on the feeder line, and the RPC control engine is responsible for controlling the opening and closing of the main power switch.

[0017] Optionally, the excitation signal is to generate a pulse-width modulated short-time power supply interruption on the feeder line.

[0018] Optionally, the excitation signal is to inject a low-power signal with characteristic frequency content on the feeder line.

[0019] Optionally, the RPC control engine is further used to perform a working status tracking report on the diagnosis and prediction device, and test and debug the functions of the diagnosis and prediction device.

[0020] In a second aspect, the present invention provides a method for diagnosing and predicting aircraft electrical circuit faults. The method is applied to the diagnosis and prediction device. The aircraft electrical circuit is equivalent to a T-type equivalent circuit model, and the equivalent circuit model includes N segments of equivalent circuits. The method includes:

[0021] Arbitrarily select the nth segment of equivalent circuit, where n is less than or equal to N;

[0022] For the xth segment of equivalent circuit, the RPC control engine generates and sends an excitation signal. The excitation signal is coupled to the feeder line through the power line interface module and excites the aircraft electrical circuit. The initial value of x is 1, and the value of x ranges from 1 to n;

[0023] Receive the response signal transmitted by the power line interface module;

[0024] Based on the model reference method and the parameter values of the 1st to the x-1th segments of equivalent circuits, determine the parameter values of the 1st to the xth segments of equivalent circuits in the equivalent circuit model;

[0025] Calculate and record the error between the parameter values of the equivalent circuits of the first to xth segments and the response signal, take the error as the xth error, and calculate the error convergence index based on the recorded x errors;

[0026] When the error convergence index is less than the preset error threshold, record the parameter values of the equivalent circuits of the first to xth segments. When x equals n, determine whether the nth equivalent circuit is a faulty segment according to the parameter values of the equivalent circuits of the first to xth segments and the normal parameter values of the preset first to xth equivalent circuits; when x is not equal to n, let x = x + 1, and return to execute the steps for the xth equivalent circuit.

[0027] Optionally, the method further includes:

[0028] When the error convergence index is greater than or equal to the preset error threshold, if x equals n, fine-tune the nth equivalent circuit according to the preset rules, or add equivalent circuits of non-faulty line segments, update n using the number of added non-faulty line segments, let x = 1, and return to execute the steps for the xth equivalent circuit; if x is not equal to n, let x = x + 1, and return to execute the steps for the xth equivalent circuit.

[0029] Optionally, the determining whether the nth equivalent circuit is a faulty segment according to the parameter values of the equivalent circuits of the first to xth segments and the normal parameter values of the preset first to xth equivalent circuits includes:

[0030] When the parameter values of the equivalent circuits of the first to xth segments are inconsistent with the normal parameter values of the preset first to xth equivalent circuits, determine that the nth equivalent circuit is a faulty segment;

[0031] When the parameter values of the equivalent circuits of the first to xth segments are consistent with the normal parameter values of the preset first to xth equivalent circuits, determine that the nth equivalent circuit is not a faulty segment, reselect the nth equivalent circuit, and return to execute the step of arbitrarily selecting the nth equivalent circuit.

[0032] Optionally, the method further includes:

[0033] Establish a trend of the parameter values changing with time based on the parameter values of the equivalent circuits of the first to xth segments;

[0034] Perform fault prediction processing on the trend of the parameter values changing with time based on the preset prediction trend technology to obtain the predicted faulty segment of the aircraft electrical circuit.

[0035] Adopting the embodiment of the present invention has the following beneficial effects:

[0036] In view of the fact that each power feeder on an aircraft is accompanied by a Remote Power Controller (RPC), an embodiment of the present application proposes a device and method for diagnosing and predicting faults in aircraft electrical circuits based on a remote power controller. The device includes: a remote power controller switch based on a digital signal processor ( Figure 3 301 in), an RPC control engine, and a power line interface module. Among them, the RPC control engine generates an excitation signal, couples the excitation signal to the feeder through the power line interface module, and sends it to the aircraft electrical circuit. When the aircraft electrical circuit is excited by the excitation signal, a response is generated. The response signal is transmitted through the feeder to the power line interface module and finally reaches the RPC control engine. By performing a T-shaped circuit equivalent on the aircraft electrical circuit, matching the equivalent circuit model with the actual aircraft electrical circuit, and using the RPC control engine, the diagnosis and prediction of faults in the aircraft electrical circuit are realized. In the embodiment of the present application, by using the inherent RPC control engine and voltage and current sensors of the remote power controller, as well as the power line interface module in the additional diagnosis and prediction device to transmit the excitation signal and receive the response signal, and processing the above response signal through the RPC control engine, the diagnosis of faults can be achieved without the need to additionally set dedicated sensors, greatly reducing the errors and waste caused by adding a large number of sensors in the aircraft electrical circuit. Without the need to transmit, collect, and process a large amount of data from these sensors, the practicality and reliability of the present application are also greatly increased. Moreover, the present application also establishes a corresponding trend of faults changing over time through the diagnosis of faults to achieve the prediction of faults in the aircraft electrical circuit, which is crucial for the safety guarantee of the aircraft electrical circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Wherein:

[0039] Figure 1 is a schematic structural diagram of the device for diagnosing and predicting faults in the aircraft electrical circuit in the embodiment of the present application;

[0040] Figure 2 is another schematic structural diagram of the device for diagnosing and predicting faults in the aircraft electrical circuit in the embodiment of the present application;

[0041] Figure 3 is another schematic structural diagram of the device for diagnosing and predicting faults in the aircraft electrical circuit in the embodiment of the present application;

[0042] Figure 4It is a schematic structural diagram of the T-equivalent circuit model of the aircraft electrical circuit in the embodiment of the present application;

[0043] Figure 5 It is a schematic flowchart of the method for diagnosing and predicting faults in the aircraft electrical circuit in the embodiment of the present application;

[0044] Figure 6 It is another schematic flowchart of the method for diagnosing and predicting faults in the aircraft electrical circuit in the embodiment of the present application. Detailed implementation manners

[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] Please refer to Figure 1 , which is a schematic structural diagram of the device for diagnosing and predicting faults in the aircraft electrical circuit in the embodiment of the present application, and includes:

[0047] A power line interface module 101 and a remote power controller RPC control engine 102 based on a digital signal processor.

[0048] Among them, one end of the power line interface module 101 is connected to the feeder, and the other end of the power line interface module 101 is connected to one end of the RPC control engine 102; the RPC control engine 102 is used to generate an excitation signal and send the excitation signal to the power line interface module 101; the power line interface module 101 is used to couple the excitation signal to the feeder and transmit it to the aircraft electrical circuit, and the aircraft electrical circuit generates a response signal when excited by the excitation signal; the power line interface module 101 is also used to receive the response signal and send it to the RPC control engine 102; the RPC control engine 102 is also used to diagnose and predict the line fault of the aircraft electrical circuit according to the response signal.

[0049] Among them, RPC refers to the Remote Power Controller.

[0050] In the embodiment of the present application, the power line interface module 101 is used to send an excitation signal and obtain the response signal of the aircraft electrical circuit, and the RPC control engine 102 processes the response signal to realize the diagnosis and prediction of faults, so that it is not necessary to obtain the aircraft electrical circuit fault signal based on a large number of sensors and a large amount of data of these sensors, realizing a more preferable possibility.

[0051] In a feasible implementation, in order to obtain the response signal of the aircraft electrical circuit, it is necessary to input a sufficient excitation signal into the aircraft electrical circuit. The excitation signal is generated by the RPC control engine 102. Among them, the excitation signal can be a pulse-width modulated short-time power supply interruption signal; the excitation signal can also be a low-power signal with characteristic frequency content.

[0052] In the implementation of this application, these two excitation signals: the short-time power supply interruption signal and the low-power signal, are both expected to significantly enhance the excitation, causing the aircraft electrical circuit to generate a transient response. The transient response meets the requirements of the model reference method and the prediction trend technology for parameter identification, while ensuring that the normal operation of the aircraft electrical circuit is not affected.

[0053] Among them, the transient response is the above-mentioned response signal. It can be understood that the complete response signal at least includes voltage value, current value, frequency signal, and pulse signal, and is not limited to these four signals mentioned in the embodiments of this application. The response signal is transmitted by the power line interface module 101 to the RPC control engine 102 for processing to achieve the diagnosis and prediction of line faults.

[0054] In a feasible implementation, the voltage value and current value in the response signal can be detected respectively and directly transmitted to the RPC control engine 102. Based on Figure 1 the structural diagram of the shown diagnosis and prediction device, please refer to Figure 2 for another structural schematic diagram of the diagnosis and prediction device for aircraft electrical circuit faults in the embodiments of this application. Among them, based on Figure 1 the shown structure, the diagnosis and prediction device may further include a voltage sensor 201 and a current sensor 202. The voltage sensor 201 and the current sensor 202 are arranged on the feeder line. One end of the voltage sensor 201 and the current sensor 202 are respectively connected to the RPC control engine 102. When the aircraft electrical circuit is excited by the excitation signal, the aircraft electrical circuit will generate a complete response signal, and the response signal contains a voltage value and a current value. The voltage sensor 201 is used to detect the voltage value, and the current sensor 202 is used to detect the current value, and the detected voltage value and current value are directly transmitted to the RPC control engine 102. Among them, the number of voltage sensors can be 1, and the number of current sensors can be 2. And in practical applications, the number of voltage sensors and current sensors can be set according to specific needs, and there is no limitation here. Further, the number of the above-mentioned voltage sensors and current sensors is much less than the number of sensors required in the prior art, so that the diagnosis and prediction of aircraft electrical circuit faults can be realized without setting a large number of sensors, reducing the errors and wastes caused by adding a large number of sensors in the aircraft electrical circuit.

[0055] In the embodiments of the present application, by setting the voltage sensor 201 and the current sensor 202, the voltage value and the current value in the response signal are detected when passing through the voltage sensor 201 and the current sensor 202 and are respectively transmitted to the RPC control engine 102, which simplifies the processing of the response signal by the RPC control engine 102 and makes the processing of the RPC control engine 102 more efficient.

[0056] In an implementable manner, the RPC control engine 102 is further configured to track and report the working status of the diagnosis and prediction device and test and debug the functions of the diagnosis and prediction device. Among them, the functions of the diagnosis and prediction device are implemented based on software, and the RPC control engine can test and debug all the software for implementing the above all functions.

[0057] Please refer to Figure 3 , which is another schematic structural diagram of the diagnosis and prediction device for aircraft electrical line faults in the embodiments of the present application:

[0058] Based on Figure 2 the structure shown, the aircraft electrical line further includes a main power switch 301. The main power switch 301 is arranged on the feeder line, and the opening and closing of the main power switch 301 are realized by the RPC control engine 102.

[0059] Among them, the main power switch 301 can be an electromechanical contactor or a semiconductor device based on MOSFET. When the main power switch 301 is an electromechanical contactor, the RPC control engine 102 functions as an intelligent contactor; when the main power switch 301 is a semiconductor device based on MOSFET, the RPC control engine 102 functions as a solid-state power controller. It can be understood that at least two of the above main power switches 301 can be selected according to different aircraft electrical lines.

[0060] Further, based on the above diagnosis and prediction device, the embodiments of the present application propose a method for diagnosing and predicting aircraft electrical line faults. This diagnosis and prediction method can be applied to the RPC control engine of the above diagnosis and prediction device. Among them, the PRC control engine can equivalent the aircraft electrical line to an equivalent circuit model. Please refer to Figure 4 , which is a schematic structural diagram of the T-type equivalent circuit model of the aircraft electrical line in the embodiments of the present application. This equivalent circuit model includes N segments of equivalent circuits.

[0061] Among them, in the field of power systems, electric wires are usually modeled as a cascade of T-type equivalent circuits, where a set of lumped parameters replaces the distributed parameters of the power line. By using this method, the aircraft electrical line is equivalent to a T-type equivalent circuit model, and the typical load circuit in the aircraft electrical line can be represented by Figure 4The model in is used for simulation. In this model, there are components in each section: resistance, inductance, shunt conductance, and capacitive susceptance. By continuously adjusting the numerical values of the component parameters, it is ensured that the output of the equivalent circuit model is consistent with the output of the actual aircraft electrical circuit. During the adjustment, the equivalent circuit model is simplified, specifically including: approximating other continuous sections except the equivalent circuit section for parameter identification as a (or a finite number of, if necessary) T-shaped structure, keeping the lumped parameters unchanged, pre-calculating the numerical values of the component parameters per unit length under normal conditions, and then diagnosing and predicting the aircraft electrical circuit by evaluating the changes in the component parameter values relative to their pre-calculated normal parameter values through the model reference method.

[0062] By equivalent the aircraft electrical circuit to a T-shaped equivalent circuit model, the diagnosis and prediction of aircraft electrical circuit faults are simplified, computing resources are reduced, the accuracy is improved, and the acquisition and processing of response signal data are made faster and more efficient.

[0063] Further, please refer to Figure 5 , which is a schematic flowchart of the method for diagnosing and predicting aircraft electrical circuit faults in the embodiment of this application. The method includes:

[0064] 501: Arbitrarily select the nth section of the equivalent circuit, where n is less than or equal to N.

[0065] 502: The xth section of the equivalent circuit, where the initial value of x is 1, and the value of x ranges from 1 to n.

[0066] 503: The RPC control engine generates and sends an excitation signal. The excitation signal is coupled to the feeder through the power line interface module and excites the aircraft electrical circuit.

[0067] 504: Receive the response signal transmitted through the power line interface module.

[0068] 505: Based on the model reference method and the parameter values of the 1st to (x - 1)th sections of the equivalent circuit, determine the parameter values of the 1st to xth sections of the equivalent circuit model;

[0069] Wherein, when x is equal to 1, then the above-mentioned determining the parameter values of the 1st to xth sections of the equivalent circuit model based on the model reference method and the parameter values of the 1st to (x - 1)th sections of the equivalent circuit can be: determining the parameter values of the 1st section of the equivalent circuit model based on the model reference method and the parameter values of the 1st section of the equivalent circuit.

[0070] 506: Calculate and record the error between the parameter values of the 1st to xth sections of the equivalent circuit and the response signal.

[0071] 507: Take the error as the xth error and calculate the error convergence index according to the x recorded errors.

[0072] 508: Determine whether the error convergence index is less than a preset error threshold. If so, proceed to step 509.

[0073] 509: Record the parameter values of the equivalent circuits from the 1st segment to the xth segment.

[0074] 510: Determine whether x is equal to n. If x is equal to n, execute step 511. If x is not equal to n, execute step 512.

[0075] 511: Compare the parameter values of the equivalent circuits from the 1st segment to the xth segment with the normal parameter values of the equivalent circuits from the 1st segment to the xth segment preset, and determine whether the nth equivalent circuit is a faulty segment.

[0076] 512: Let x = x + 1, and return to execute the foregoing step 503.

[0077] It can be understood that the model reference method in step 505 is a general technique in the prior art. Among them, first, the parameter values of the equivalent circuits from the 1st segment to the (x - 1)th segment are obtained through the model reference method, that is, the foregoing simplification of the equivalent circuit model: approximate other continuous segments except the equivalent circuit segment for parameter identification as a (or a finite number of, if necessary) T-type structure, and keep the lumped parameters stable.

[0078] Among them, calculating the error convergence index based on the recorded x errors in step 507 belongs to the prior art. The preset error threshold in step 508 is based on the normal response time series determined by the foregoing different excitation signals, and can be obtained by using the prior art. When the error convergence index is less than the preset error threshold, it can be determined that the error between the equivalent circuit model and the aircraft electrical circuit is within the normal range, that is, the output of the equivalent circuit model is basically the same as the output of the actual aircraft electrical circuit. At this time, the parameter identification result of the equivalent circuit model is basically the same as the diagnosis and prediction of the actual aircraft electrical circuit fault.

[0079] In a realizable manner, the normal parameter values of the equivalent circuits from the 1st segment to the xth segment preset are obtained by performing parameter identification on the parameter values of its equivalent circuit based on the model reference method when the aircraft electrical circuit is operating normally, that is, without failure. Through these normal parameter values, they can be compared with the real-time parameter values generated in the implementation of the method of this application embodiment. If there is a change, it is regarded as a faulty segment. If the two are consistent, it is normal and there is no failure.

[0080] For example, when a T-equivalent circuit is used to equivalent an actual aircraft electrical circuit, which is equivalent to 10 sections of equivalent circuits, and the 3rd section of equivalent circuit is selected for fault diagnosis and prediction, it is necessary to start from the 1st section of equivalent circuit. The RPC control engine generates and sends an excitation signal, which is coupled to the feeder through the power line interface module and excites the aircraft electrical circuit. The response signal transmitted through the power line interface module is received. Based on the model reference method, the parameter values of the 1st section of equivalent circuit are identified, the parameter values of the 1st section of equivalent circuit are determined, the error between the parameter values of the 1st section of equivalent circuit and the response signal is calculated and recorded. The error is used as the 1st error, and the error convergence index is calculated according to the 1 recorded error. When the error convergence index I is less than the preset error threshold, the parameter values of the 1st section of equivalent circuit are recorded, and let x = 1 + 1, that is, x = 2.

[0081] Continue to process the 2nd section of equivalent circuit. After the same above steps, the RPC control engine can determine the parameter values of the 1st to 2nd sections of equivalent circuit in the equivalent circuit model, calculate and record the error between the parameter values of the 1st to 2nd sections of equivalent circuit and the response signal. The error is used as the 2nd error, and the error convergence index is calculated according to the 2 recorded errors; when the error convergence index is less than the preset error threshold, the parameter values of the 1st to 2nd sections of equivalent circuit are recorded, and let x = 2 + 1, that is, x = 3;

[0082] Continue to process the 3rd section of equivalent circuit. After the same above steps, the RPC control engine receives the response signal. Based on the model reference method and the parameter values of the 1st to 2nd sections of equivalent circuit, the parameter values of the 1st to 3rd sections of equivalent circuit in the equivalent circuit model are determined, calculate and record the error between the parameter values of the 1st to 3rd sections of equivalent circuit and the response signal. The error is used as the 3rd error, and the error convergence index is calculated according to the 3 recorded errors. When the error convergence index is less than the preset error threshold, the parameter values of the 1st to 3rd sections of equivalent circuit are recorded. At this time, the pre-selected equivalent circuit section has been processed, so it is possible to directly determine whether the 3rd section of equivalent circuit is a faulty section according to the parameter values of the 1st to 3rd sections of equivalent circuit and the normal parameter values of the preset 1st to 3rd sections of equivalent circuit.

[0083] In the embodiment of the present application, through steps 505 and 508, the output error between the equivalent circuit model and the aircraft electrical circuit is within the normal range, so that the fault diagnosis and prediction of the aircraft electrical circuit can be transformed into the judgment of the identification result of the parameter values of the equivalent circuit model, realizing efficient fault diagnosis and prediction.

[0084] Based on Figure 5 the shown flowchart, please refer to Figure 6, which is another process schematic diagram of the method for diagnosing and predicting aircraft electrical line faults in the embodiments of the present application, includes:

[0085] 501: Arbitrarily select the nth equivalent circuit, where n is less than or equal to N.

[0086] 502: The xth equivalent circuit, where the initial value of x is 1, and the value of x ranges from 1 to n.

[0087] 503: The RPC control engine generates and sends an excitation signal, and the excitation signal is coupled to the feeder through the power line interface module and excites the aircraft electrical line.

[0088] 504: Receive the response signal transmitted through the power line interface module.

[0089] 505: Based on the model reference method and the parameter values of the 1st to (x - 1)th equivalent circuits, determine the parameter values of the 1st to xth equivalent circuits in the equivalent circuit model;

[0090] Among them, when x is equal to 1, then the above-mentioned determining the parameter values of the 1st to xth equivalent circuits in the equivalent circuit model based on the model reference method and the parameter values of the 1st to (x - 1)th equivalent circuits can be to determine the parameter values of the 1st equivalent circuit in the equivalent circuit model based on the model reference method and the parameter values of the 1st equivalent circuit.

[0091] 506: Calculate and record the error between the parameter values of the 1st to xth equivalent circuits and the response signal.

[0092] 507: Take the error as the xth error, and calculate the error convergence index according to the recorded x errors.

[0093] 508: Determine whether the error convergence index is less than the preset error threshold. If not, execute step 601.

[0094] 601: Determine whether x is equal to n. If x is equal to n, execute step 602. If x is not equal to n, execute step 603.

[0095] 602: Fine-tune the nth equivalent circuit according to the preset rules, or add the equivalent circuits of non-faulty line segments, and update n with the number of added non-faulty line segments, and return to execute step 502.

[0096] 603: Let x = x + 1, and return to execute step 503.

[0097] For example, in the foregoing example, for the step of processing the 3rd equivalent circuit:

[0098] For the equivalent circuit of the third segment, after the same above steps, calculate the error convergence index according to the three recorded errors. When the error convergence index is greater than or equal to the preset error threshold, record the parameter values of the equivalent circuits of the first to third segments. At this time, it indicates that the error between the equivalent circuit model and the aircraft electrical circuit exceeds the normal range. One equivalent circuit segment can be added to the third segment of the equivalent circuit. After the update, n = 4 and N = 11 at this time. Let x = 1, and then return to execute the aforementioned steps for the equivalent circuit of the first segment.

[0099] It can be understood that in the above method: according to the parameter values of the equivalent circuits of the first to x segments and the preset normal parameter values of the equivalent circuits of the first to x segments, determine whether the nth segment of the equivalent circuit is a faulty segment. Specifically, it may include:

[0100] Judge whether the parameter values of the equivalent circuits of the first to x segments are consistent with the preset normal parameter values of the equivalent circuits of the first to x segments; when the parameter values of the equivalent circuits of the first to x segments are not consistent with the preset normal parameter values of the equivalent circuits of the first to x segments, it can be determined that the nth segment is a faulty segment, and record the parameter values and the n value at this time; when the parameter values of the equivalent circuits of the first to x segments are consistent with the preset normal parameter values of the equivalent circuits of the first to x segments, it is determined that the nth segment is not a faulty segment, and return to execute step 501.

[0101] In an implementable manner, when it is determined that the nth segment is a faulty segment, step 501 can be returned to execute to diagnose and predict faults in other equivalent circuit segments.

[0102] It can be understood that when the parameter values of the equivalent circuits of the first to x segments are consistent with the preset normal parameter values of the equivalent circuits of the first to x segments, it indicates that the parameter values of the nth segment are normal, so the nth segment is a normal segment, and return to execute step 501 to diagnose and predict other equivalent circuit segments.

[0103] In the embodiments of the present application, first, the aircraft electrical circuit is equivalent to a T-type equivalent circuit model, and then the equivalent circuit model and the aircraft electrical circuit are optimized and iterated to make them highly matched, that is, the output of their parameter values is highly consistent. At this time, the faults of the aircraft electrical circuit can be represented by the change of the parameter values of the equivalent circuit model; based on the model reference method, parameter identification is performed on the parameter values, and the obtained parameter values are compared with the normal parameter values to determine the faulty segment. This makes the aforementioned diagnostic and prediction device consume fewer resources and be more practical.

[0104] Among them, the above method further includes fault prediction:

[0105] Since corresponding data is recorded in each iteration, and the data includes the parameter values of the equivalent circuits from the first segment to the x-th segment, a trend model of the parameter values changing over time can be established according to time. Based on the preset prediction trend technology, a fault prediction process is performed on the trend of the parameter values changing over time to obtain the predicted fault segments of the aircraft electrical circuit.

[0106] Among them, the preset prediction trend technology is an existing technology, including but not limited to:

[0107] Robust regression - a technique for implementing piecewise regression and using a convex hull to complete segmentation, Monotonic regression - a univariate regression technique based on a dynamic system following a Poisson process, Partially specified distribution smoothing - a technique for implementing a Kalman filter using a partially specified state and noise covariance matrix, Hybrid trend model - a concept where the model evolves in a hybrid state space (continuous + discrete) for the prediction vector, and a technique for using a Kalman filter to track the state evolution of the hybrid state space.

[0108] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0109] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for diagnosing and predicting aircraft electrical circuit faults, characterized in that, The described diagnosis and prediction method is applied to a diagnosis and prediction device for aircraft electrical circuit faults. The diagnosis and prediction device includes: A power line interface module and a remote power controller RPC control engine based on a digital signal processor; The aircraft electrical circuit is equivalent to a T-type equivalent circuit model. The equivalent circuit model includes N segments of equivalent circuits. The method includes: Arbitrarily select the nth segment of equivalent circuit, where n is less than or equal to N; For the xth segment of equivalent circuit, the RPC control engine generates and sends an excitation signal. The excitation signal is coupled to the feeder through the power line interface module and excites the aircraft electrical circuit. The initial value of x is 1, and the value of x ranges from 1 to n; Receive the response signal transmitted by the power line interface module; Based on the parameter values of the 1st to (x - 1)th segments of equivalent circuit by the model reference method, determine the parameter values of the 1st to xth segments of equivalent circuit in the equivalent circuit model; Calculate and record the error between the parameter values of the 1st to xth segments of equivalent circuit and the response signal. Take the error as the xth error, and calculate the error convergence index according to the recorded x errors; When the error convergence index is less than the preset error threshold, record the parameter values of the 1st to xth segments of equivalent circuit. And when x is equal to n, determine whether the nth segment of equivalent circuit is a faulty segment according to the parameter values of the 1st to xth segments of equivalent circuit and the normal parameter values of the preset 1st to xth segments of equivalent circuit; when x is not equal to n, let x = x + 1, and return to execute the step for the xth segment of equivalent circuit.

2. The method according to claim 1, characterized in that, The method further includes: When the error convergence index is greater than or equal to the preset error threshold, if x is equal to n, fine-tune the nth segment of equivalent circuit according to a preset rule, or add equivalent circuits of non-faulty line segments, and update n with the number of added non-faulty line segments. Let x = 1, and return to execute the step for the xth segment of equivalent circuit; if x is not equal to n, let x = x + 1, and return to execute the step for the xth segment of equivalent circuit.

3. The method according to claim 1, wherein The determination of whether the nth segment of equivalent circuit is a faulty segment according to the parameter values of the 1st to xth segments of equivalent circuit and the normal parameter values of the preset 1st to xth segments of equivalent circuit includes: When the parameter values of the 1st to xth segments of equivalent circuit are inconsistent with the normal parameter values of the preset 1st to xth segments of equivalent circuit, determine that the nth segment of equivalent circuit is a faulty segment; When the parameter values of the 1st to xth segments of equivalent circuit are consistent with the normal parameter values of the preset 1st to xth segments of equivalent circuit, determine that the nth segment of equivalent circuit is not a faulty segment, re-select the nth segment of equivalent circuit, and return to execute the step of arbitrarily selecting the nth segment of equivalent circuit.

4. The method according to claim 1, characterized in that, The method further includes: Establish a trend of parameter values changing with time according to the parameter values of the 1st to xth segments of equivalent circuit; Perform fault prediction processing on the trend of parameter values changing with time based on a preset prediction trend technology to obtain the predicted faulty segment of the aircraft electrical circuit.

5. A device for diagnosing and predicting aircraft electrical circuit faults, characterized in that, The diagnostic and prediction device for aircraft electrical line faults is used to execute the method according to any one of claims 1 to 4. The diagnostic and prediction device includes: A power line interface module and a remote power controller RPC control engine based on a digital signal processor; One end of the power line interface module is connected to the feeder, and the other end of the power line interface module is connected to one end of the RPC control engine; The RPC control engine is used to generate an excitation signal and send the excitation signal to the power line interface module; The power line interface module is used to couple the excitation signal to the feeder and transmit it to the aircraft electrical line. When the aircraft electrical line is excited by the excitation signal, a response signal is generated; The power line interface module is also used to receive the response signal and send it to the RPC control engine; The RPC control engine is also used to diagnose and predict the line faults of the aircraft electrical line according to the response signal.

6. The device according to claim 5, wherein The diagnostic and prediction device also includes a voltage sensor and a current sensor. The voltage sensor and the current sensor are arranged on the feeder, and one ends of the voltage sensor and the current sensor are respectively connected to the RPC control engine; The voltage sensor is used to detect the voltage value when the aircraft electrical line is excited by the excitation signal and transmit the voltage value to the RPC control engine; The current sensor is used to detect the current value when the aircraft electrical line is excited by the excitation signal and transmit the current value to the RPC control engine.

7. The device according to claim 5, characterized in that, The aircraft electrical line also includes a main power switch, specifically including: The main power switch is arranged on the feeder, and the RPC control engine is responsible for controlling the opening and closing of the main power switch.

8. The device according to claim 5, wherein The excitation signal is a short-time power supply interruption with pulse width modulation generated on the feeder.

9. The device according to claim 5, characterized in that, The excitation signal is a low-power signal with characteristic frequency content injected into the feeder.

10. The device according to claim 5, characterized in that, The RPC control engine is also used to perform a working state tracking report on the diagnostic and prediction device and test and debug the functions of the diagnostic and prediction device.

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