Engine fault detection method, device and equipment based on single sensor and medium

Abstract

The invention discloses an engine fault detection method, device and equipment based on a single sensor and a medium, and relates to the technical field of fault detection. The method comprises the following steps: acquiring an eddy current original signal and an optical fiber pulse signal of the optical fiber eddy current composite sensor; the optical fiber eddy current composite sensor is installed at the position of an aero-engine casing. Calculating a blade radial displacement signal according to the eddy current original signal, and calculating a blade circumferential displacement signal according to the optical fiber pulse signal; filtering the blade circumferential displacement signal to obtain a target circumferential displacement signal; resampling the radial displacement signal of the blade to obtain a time sequence blade tip clearance signal; and engine blade fault information is determined according to the target circumferential displacement signal and the time sequence blade tip gap signal. Thus, the eddy current original signal and the optical fiber pulse signal are directly measured through the single sensor to detect faults, the transmission path is shortened, the diagnosis sensitivity and accuracy and the measuring point utilization rate are improved, and the sensor arrangement complexity is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of fault detection, and particularly to an engine fault detection method, device, equipment and medium based on a single sensor. Background Art

[0002] Currently, the condition monitoring of aeroengines mainly relies on multi-sensor fusion methods, which usually include an acceleration sensor for measuring casing vibration, a displacement sensor for measuring the rotor center orbit, a tip sensor for measuring blade vibration, and a pressure sensor for detecting surge. However, these methods require multiple sensors to work together, with a large number of measurement points and low sensitivity to early weak faults. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to overcome the deficiencies in the prior art, and provide an engine fault detection method, device, equipment and medium based on a single sensor, which is used to directly obtain the eddy current original signal and the fiber optic pulse signal by installing a single composite sensor at the casing position of the aeroengine, and further diagnose and warn multiple faults of the engine by using this information, so as to realize the efficient monitoring of the aeroengine with a single measurement point and multi-source perception.

[0004] The present invention provides the following technical solutions:

[0005] In a first aspect, the present application proposes an engine fault detection method based on a single sensor, including: obtaining the eddy current original signal and the fiber optic pulse signal of the fiber optic eddy current composite sensor; the fiber optic eddy current composite sensor is installed at the casing position of the aeroengine; calculating the blade radial displacement signal according to the eddy current original signal, and calculating the blade circumferential displacement signal according to the fiber optic pulse signal; filtering the blade circumferential displacement signal to obtain the target circumferential displacement signal; resampling the blade radial displacement signal to obtain the time series tip clearance signal; determining the engine blade fault information according to the target circumferential displacement signal and the time series tip clearance signal.

[0006] In an embodiment, the calculating the blade radial displacement signal according to the eddy current original signal and the calculating the blade circumferential displacement signal according to the fiber optic pulse signal include: filtering the eddy current original signal to obtain the eddy current filtered signal; obtaining the current speed of the aeroengine and determining the dynamic sensitivity corresponding to the current speed; converting the eddy current filtered signal into the blade radial displacement signal according to the dynamic sensitivity; performing time point number conversion on the fiber optic pulse signal to obtain the measured time point number; determining the time point number difference between the preset theoretical time point number and the measured time point number, and obtaining the blade circumferential displacement signal according to the product of the time point number difference and the current speed.

[0007] In one embodiment, resampling the blade radial displacement signal to obtain a time-series tip clearance signal includes: resampling the blade radial displacement signal to obtain a blade tip clearance value; correcting and compensating the blade tip clearance value based on a preset static machining dimension of the blade to obtain a corrected blade tip clearance value; and performing a traveling wave analysis on the corrected blade tip clearance value to obtain the time-series tip clearance signal.

[0008] In one embodiment, determining engine blade fault information according to the target circumferential displacement signal includes: obtaining a single blade signal according to the target circumferential displacement signal, and obtaining the blade phase according to the single blade signal; calculating a coefficient of variation according to the blade phase to obtain a variation characteristic parameter; obtaining a phase characteristic evaluation result according to the variation characteristic parameter; obtaining an amplitude warning threshold according to the blade phase, and obtaining an amplitude characteristic evaluation result according to the amplitude warning threshold and the target circumferential displacement signal; and determining that the engine blade fault information is surge information or resonance information or foreign object impact fault information according to the phase characteristic evaluation result and the amplitude characteristic evaluation result.

[0009] In one embodiment, determining engine blade fault information according to the time-series tip clearance signal includes: fitting the time-series tip clearance signal to obtain a radial relative motion state; obtaining an unbalance amplitude and an unbalance phase according to the radial relative motion state based on a cross-correlation algorithm; and determining that the engine blade fault information is engine unbalance fault information according to the unbalance amplitude and the unbalance phase.

[0010] In one embodiment, determining engine blade fault information according to the time-series tip clearance signal includes: detecting the time-series tip clearance signal based on an anomaly judgment algorithm to obtain an anomaly signal; performing time-frequency analysis on the anomaly signal to obtain a time-frequency energy spectrum; and if there is a rubbing feature in the time-frequency energy spectrum, determining that the engine blade fault information is rubbing fault information.

[0011] In one embodiment, the method further includes: performing discrete wavelet decomposition on the blade circumferential displacement signal to obtain wavelet coefficients; calculating the squared modulus of the wavelet coefficients, and obtaining a time-frequency spectrogram according to the squared modulus; determining the blade vibration frequency according to the time-frequency spectrogram; determining a frequency change rate according to the blade vibration frequency and a preset modal frequency; and if the frequency change rate is greater than a preset threshold, determining that the engine blade fault information is blade crack information.

[0012] In a second aspect, the present application provides an engine fault detection device based on a single sensor, including:

[0013] An acquisition module, configured to acquire the eddy current original signal and the optical fiber pulse signal of the fiber optic eddy current composite sensor; the fiber optic eddy current composite sensor is installed at the position of the aero-engine casing;

[0014] A calculation module, configured to calculate the blade radial displacement signal according to the eddy current original signal, and calculate the blade circumferential displacement signal according to the optical fiber pulse signal;

[0015] A processing module, configured to filter the blade circumferential displacement signal to obtain a target circumferential displacement signal; resample the blade radial displacement signal to obtain a time-series tip clearance signal;

[0016] A determination module, configured to determine the engine blade fault information according to the target circumferential displacement signal and the time-series tip clearance signal.

[0017] In a third aspect, the present application provides a computer device, including a memory and a processor, where the memory stores a computer program, and when the computer program is executed by the processor, it implements the single-sensor-based engine fault detection method as described in the first aspect.

[0018] In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, it implements the single-sensor-based engine fault detection method as described in the first aspect.

[0019] The single-sensor-based engine fault detection method, device, equipment and medium disclosed in the present application acquire the eddy current original signal and the optical fiber pulse signal of the fiber optic eddy current composite sensor; the fiber optic eddy current composite sensor is installed at the position of the aero-engine casing; calculate the blade radial displacement signal according to the eddy current original signal, and calculate the blade circumferential displacement signal according to the optical fiber pulse signal; filter the blade circumferential displacement signal to obtain a target circumferential displacement signal; resample the blade radial displacement signal to obtain a time-series tip clearance signal; determine the engine blade fault information according to the target circumferential displacement signal and the time-series tip clearance signal. In this way, by directly measuring the eddy current original signal and the optical fiber pulse signal that reflect the dynamic characteristics of the blade with a single sensor, the transmission path is shortened, the sensitivity, accuracy and measurement point utilization rate of diagnosis are improved, the complexity of sensor arrangement is reduced, and it has the advantages of strong real-time performance, high diagnosis accuracy and wide application range. It can be used for the state monitoring, fault warning and health management of aero-engines, and improve the safety and reliability of engine operation. Description of the Drawings

[0020] To more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the protection scope of the present invention. In each drawing, similar components are numbered similarly.

[0021] Figure 1 Fig. shows a schematic flow chart of an engine fault detection method based on a single sensor proposed in this embodiment;

[0022] Figure 2 Fig. shows a schematic diagram of the synchronous monitoring principle of blade vibration and tip clearance under the condition of a single sensor;

[0023] Figure 3 Fig. shows another schematic flow chart of an engine fault detection method based on a single sensor proposed in this embodiment;

[0024] Figure 4 Fig. shows yet another schematic flow chart of an engine fault detection method based on a single sensor proposed in this embodiment;

[0025] Figure 5 Fig. shows a schematic diagram of a single-sensor resonance early warning case based on tip timing proposed in this embodiment;

[0026] Figure 6 Fig. shows a schematic diagram of a single-sensor surge early warning case based on tip timing proposed in this embodiment;

[0027] Figure 7 Fig. shows a schematic diagram of the principle of rotor vibration fitting and unbalance parameter identification based on tip clearance proposed in this embodiment;

[0028] Figure 8 Fig. shows a schematic diagram of an actual diagnosis case of unbalance parameter identification proposed in this embodiment;

[0029] Figure 9 Fig. shows a schematic diagram of an actual case of time-domain early warning of rub-impact fault based on tip clearance proposed in this embodiment;

[0030] Figure 10 Fig. shows a schematic diagram of an actual case of frequency-domain diagnosis of rub-impact fault based on tip clearance proposed in this embodiment;

[0031] Figure 11 Fig. shows a schematic structural diagram of an engine fault detection device based on a single sensor proposed in this embodiment.

[0032] Explanation of the reference numerals in the drawings:

[0033] 1101 - Acquisition module; 1102 - Calculation module; 1103 - Processing module; 1104 - Determination module. Detailed implementation manners

[0034] 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.

[0035] Generally, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0036] In the following, the terms "including", "having" and their cognates that can be used in various embodiments of the present invention are only intended to represent specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be construed as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or increasing the possibility of one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0037] In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0038] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the various embodiments of the present invention belong. The terms (such as those defined in a general-use dictionary) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning unless clearly defined in the various embodiments of the present invention.

[0039] Embodiment 1

[0040] The embodiment of the present disclosure provides a single-sensor-based engine fault detection method, which is used to directly obtain eddy current original signals and optical fiber pulse signals by installing a single composite sensor at the position of the aeroengine casing, and further diagnose and give early warnings about various engine faults by using this information, so as to realize the efficient monitoring of aeroengines with single measurement points and multi-source perception.

[0041] Please refer to Figure 1 , the single-sensor-based engine fault detection method includes steps S101 to S104, and the following is a detailed description of each step.

[0042] Step S101: Obtain the eddy current raw signal and the optical fiber pulse signal of the fiber-optic eddy current composite sensor; the fiber-optic eddy current composite sensor is installed at the position of the aero-engine casing.

[0043] In this embodiment, the fiber-optic eddy current composite sensor is a fiber-optic - eddy current coupled blade vibration - tip clearance composite sensor. The fiber-optic - eddy current coupled blade vibration - tip clearance composite sensor is installed at the position of the aero-engine casing, and the eddy current raw signal and the optical fiber pulse signal of the fiber-optic eddy current composite sensor are synchronously and highly sampled through the upper computer monitoring system. The principle of synchronous monitoring of blade vibration and tip clearance under the condition of a single sensor is as Figure 2 shown.

[0044] It should be noted that the fiber-optic - eddy current coupled blade vibration - tip clearance composite sensor is installed at a single point on the casing. The center of the sensor probe needs to be aligned with the tip of the blade, and the sensor probe cannot interfere with the rotation path of the blade. Due to the high-frequency vibration and high linear velocity of the blade, both the eddy current raw signal and the optical fiber pulse signal require high-frequency sampling.

[0045] It should be additionally noted that by using the method of arranging a single fiber-optic - eddy current composite sensor at the position of the engine casing to complete the synchronous measurement of blade vibration and tip clearance, compared with the traditional multi-sensor system, the number of measurement points is reduced, the sensor arrangement is simplified, and the complexity and maintenance cost of the monitoring system are reduced.

[0046] Step S102: Calculate the blade radial displacement signal according to the eddy current raw signal, and calculate the blade circumferential displacement signal according to the optical fiber pulse signal.

[0047] In this embodiment, the eddy current raw signal reflects the radial displacement of the engine blade, and the optical fiber pulse signal reflects the circumferential displacement of the engine blade. Therefore, the eddy current raw signal can be converted into the blade radial displacement signal, and the optical fiber pulse signal can be converted into the blade circumferential displacement signal. The optical fiber pulse signal and the eddy current raw signal are preliminarily processed through a signal preprocessing method, improving the data quality and ensuring the reliability and analysis accuracy of the data.

[0048] Please refer to Figure 3 , in a specific embodiment, step S102 includes steps S1021 to S1025, and the following is a detailed description of each step.

[0049] Step S1021: Filter the eddy current raw signal to obtain the eddy current filtered signal.

[0050] In this embodiment, the eddy current original signal is filtered to remove the noise introduced by high-frequency sampling, and the eddy current filtered signal is obtained.

[0051] Step S1022: Obtain the current rotational speed of the aero-engine and determine the dynamic sensitivity corresponding to the current rotational speed.

[0052] In this embodiment, the dynamic sensitivity represents the response characteristic of the sensor output varying with the rotational speed. Usually, it is a non-linear function and needs to be calibrated through experiments. Query the dynamic sensitivity corresponding to the current rotational speed of the aero-engine.

[0053] Step S1023: Convert the eddy current filtered signal into the blade radial displacement signal according to the dynamic sensitivity.

[0054] In this embodiment, analyze the eddy current original signal, and calculate the rotor rotation period T and the arrival time difference t between adjacent blades according to the characteristic blade w . The specific calculation formula is: T = t OPR,p+1 -t OPR,p , t w = T / n b , where n b represents the number of blades, OPR represents the key-phase blade, and p represents the number of turns.

[0055] Further, calculate the time range when a single blade arrives according to the rotor rotation period T and the arrival time difference t between adjacent blades w , and extract the peak value within this time range. Each peak point is the extracted tip clearance voltage.

[0056] Further, convert the tip clearance voltage V into the tip clearance value D according to the dynamic sensitivity S, that is, the blade radial displacement signal. The specific expression is: D = V / S.

[0057] Step S1024: Perform a time point number conversion on the optical fiber pulse signal to obtain the measured time point number.

[0058] In this embodiment, convert the optical fiber pulse signal into the measured time point number through a counter.

[0059] Step S1025: Determine the time point number difference between the preset theoretical time point number and the measured time point number, and obtain the blade circumferential displacement signal according to the product of the time point number difference and the current rotational speed.

[0060] In this embodiment, determine the time point number difference ΔT between the preset theoretical time point number and the measured time point number, and obtain the blade circumferential displacement signal D according to the product of the time point number difference ΔT and the current rotational speed V c . The specific expression is: D c= VΔT.

[0061] Step S103: Filter the circumferential displacement signal of the blade to obtain a target circumferential displacement signal; resample the radial displacement signal of the blade to obtain a time-series tip clearance signal.

[0062] In this embodiment, the circumferential displacement signal of the blade is filtered to obtain a target circumferential displacement signal. For example, based on the data smoothing and differential calculation (Savitzky-Golay) method of local polynomial least-squares fitting, the circumferential displacement signal of the blade is smoothed and denoised, and the offset information is removed to obtain a target circumferential displacement signal with high-frequency noise information removed. At the same time, the radial displacement signal of the blade is resampled to obtain a time-series tip clearance signal.

[0063] Please refer to Figure 4 , in a specific embodiment, step S103 includes steps S1031 to S1033, and the following will explain each step in detail.

[0064] Step S1031: Resample the radial displacement signal of the blade to obtain the blade tip clearance value.

[0065] In this embodiment, the radial displacement signal of the blade is resampled to obtain the blade tip clearance value of each blade.

[0066] Step S1032: Based on the preset static machining size of the blade, correct and compensate the blade tip clearance value to obtain a corrected blade tip clearance value.

[0067] In this embodiment, the preset static machining size D of the blade is used s to correct and compensate the blade tip clearance value D to obtain a corrected blade tip clearance value D B . The specific expression is: D B = D + D s .

[0068] Step S1033: Perform traveling wave analysis on the corrected blade tip clearance value to obtain the time-series tip clearance signal.

[0069] In this embodiment, traveling wave analysis is performed on the corrected blade tip clearance value to obtain the time-series tip clearance changes of different blades to obtain a time-series tip clearance signal.

[0070] It should be noted that the average tip clearance and the minimum tip clearance of the operating cycle of each blade can be calculated according to the time-series tip clearance changes. The average tip clearance can be used to represent the operating condition of the engine, and the minimum tip clearance can also be used for fault warning of aeroengines.

[0071] Step S104: Determine the engine blade fault information based on the target circumferential displacement signal and the timing tip clearance signal.

[0072] In this embodiment, by comprehensively analyzing the target circumferential displacement signal reflecting the vibration or deformation of the blade in the circumferential direction and the timing tip clearance signal reflecting the change of the clearance between the blade and the casing over time, the engine blade fault can be effectively identified, the sensitivity and accuracy of fault detection can be improved, the health management level of the aeroengine can be enhanced, and the problems of complex multi-sensor layout, difficult data synchronization and fusion, strong independence and lack of unity in the existing aeroengine condition monitoring methods can be solved.

[0073] In a specific embodiment, step S104 includes: obtaining the single-blade signal according to the target circumferential displacement signal, and obtaining the blade phase according to the single-blade signal; calculating the coefficient of variation according to the blade phase to obtain the variation characteristic parameter; obtaining the phase characteristic evaluation result according to the variation characteristic parameter; obtaining the amplitude warning threshold according to the blade phase, and obtaining the amplitude characteristic evaluation result according to the amplitude warning threshold and the target circumferential displacement signal; determining that the engine blade fault information is surge information or resonance information or foreign object strike fault information according to the phase characteristic evaluation result and the amplitude characteristic evaluation result.

[0074] In this embodiment, the single-blade signal of each blade is obtained according to the target circumferential displacement signal, and the blade phase of each blade is calculated according to each single-blade signal The specific expression is: where A is the tip circumferential displacement coefficient, is the phase offset information.

[0075] Further, according to the blade phase of each blade the phase standard deviation is calculated and the average phase difference and according to the phase standard deviation and the average phase difference the coefficient of variation is calculated to obtain the variation characteristic parameter U. The specific expression is:

[0076] Further, the phase characteristic evaluation result is obtained according to the variation characteristic parameter. Exemplarily, if the variation characteristic parameter is lower than the preset interval, the corresponding phase characteristic return value is set to "-1"; if the variation characteristic parameter exceeds the preset interval, the corresponding phase characteristic return value is set to "1". Among them, the preset interval can be (-60, +60), and this embodiment does not limit it here.

[0077] Further, the amplitude warning threshold D is obtained according to the blade phase max. The specific expression is as follows: In the formula, N is the number of rotor blades.

[0078] Furthermore, an amplitude feature evaluation result is obtained based on the amplitude warning threshold and the target circumferential displacement signal. Exemplarily, if the vibration amplitude of the blade, i.e., the target circumferential vibration displacement signal, exceeds the amplitude warning threshold, the amplitude feature return value is "large".

[0079] Furthermore, the engine blade fault information is determined to be surge information or resonance information or foreign object strike fault information based on the phase feature evaluation results of each blade and the amplitude feature evaluation results of each blade. Exemplarily, if the phase feature return value of all blades is "-1" and the amplitude feature return value is "large", the engine blade fault is resonance; if the phase feature return value of all blades is "1" and the amplitude feature return value is "large", the engine blade fault is surge; if the phase feature return value of some blades is "1" and the amplitude feature return value is "large", the engine blade fault is foreign object strike fault.

[0080] Such as Figure 5 The tip timing monitoring data when the compressor shown in the figure undergoes resonance. The resonance starts at the 200th revolution and recovers after the 530th revolution. In the figure are respectively the displacement vibration waveform, amplitude feature, alarm threshold, and phase feature of the blade. It can be seen that when resonance occurs, the amplitude feature curve exceeds the alarm threshold, and the phase feature curve shows -1. After the resonance ends, the amplitude feature and phase feature curves recover.

[0081] Such as Figure 6 The tip timing monitoring data in the surge section of the compressor shown in the figure. The surge starts at the 356th revolution and recovers after the 447th revolution. In the figure are respectively the displacement vibration waveform, amplitude feature, alarm threshold, and phase feature of the blade. It can be seen that when the surge occurs, the amplitude feature curve exceeds the alarm threshold, and the phase feature curve shows 1. After the surge ends, the amplitude feature and phase feature curves recover.

[0082] In a specific embodiment, step S104 includes: fitting the timing tip clearance signal to obtain the radial relative motion state; based on the cross-correlation algorithm, obtaining the unbalance amplitude and unbalance phase according to the radial relative motion state; and determining the engine blade fault information to be engine unbalance fault information according to the unbalance amplitude and the unbalance phase.

[0083] In this embodiment, the timing tip clearance signal is fitted to restore the discrete timing tip clearance to the continuous radial relative motion state between the blade and the casing within the rotation period of the aeroengine, so as to reflect the overall vibration characteristics of the rotor. The fitting methods include polynomial fitting and sine wave fitting methods.

[0084] Further, based on the cross-correlation algorithm, the amplitude and phase of the rotor's fundamental frequency component are extracted from the radial relative motion state to obtain the unbalance amplitude and unbalance phase, thereby identifying the rotor unbalance vibration parameters.

[0085] Among them, the identified unbalance phase is calculated with the characteristic blade as a reference under the condition of no key phase, that is, identifying the unbalance amplitude and unbalance phase only relies on a single sensor.

[0086] Further, based on the unbalance amplitude and unbalance phase, it is determined that the current engine blade fault is an engine unbalance fault. The principle of rotor vibration fitting and unbalance parameter identification based on the tip clearance is as Figure 7 shown. On the left is the engine main shaft and an impeller of the engine. Under the rotating state, the engine rotating shaft is vibrating in real time. The tip clearance signal reflects the radial displacement of the blade, that is, it can reflect the radial vibration of the rotor; A practical example of the time-domain early warning of the rubbing fault based on the tip clearance is as Figure 8 shown. The effect display diagram of diagnosing unbalance through the tip clearance signal: The unbalance-related component is the signal after filtering, fitting, decomposing and reconstructing the tip clearance signal. The data calculated by this method is the result of cross-correlation calculation (representing the unbalance amplitude and unbalance phase). The numerical simulation setting is the true value. It can be seen that the true value is basically consistent with the calculation result of this method, which is used to reflect the practical effect of the proposed calculation method.

[0087] In a specific embodiment, step S104 includes: detecting the sequential tip clearance signal based on the anomaly judgment algorithm to obtain an anomaly signal; performing time-frequency analysis on the anomaly signal to obtain a time-frequency energy spectrum; if there is a rubbing feature in the time-frequency energy spectrum, it is determined that the engine blade fault information is rubbing fault information.

[0088] In this embodiment, the sequential tip clearance signal is detected for anomalies based on the anomaly judgment algorithm to determine an anomaly signal. At this time, it can be warned that the aeroengine is in an abnormal state. Further, time-frequency analysis is performed on the anomaly signal to obtain a time-frequency energy spectrum. If there is a rubbing feature in the time-frequency energy spectrum, it is determined that the engine blade fault is a rubbing fault. The rubbing feature includes the peak cutting phenomenon when rubbing occurs and the non-stationary phenomenon of time-frequency. Among them, the specific expression of performing time-frequency analysis on the anomaly signal is: In the formula, D c is the decomposed anomaly signal, y i is each decomposed component, r is the decomposition residual component, is the analytical solution of each component, that is, it represents the solution result of the previous equation. N represents the number of decomposed components, j is the imaginary unit, a i is the amplitude of the i-th decomposed component, represents the phase angle of the i-th decomposed component.

[0089] In a specific embodiment, the method further includes: performing discrete wavelet decomposition on the circumferential displacement signal of the blade to obtain wavelet coefficients; calculating the modulus square of the wavelet coefficients, and obtaining a time-frequency spectrum diagram according to the modulus square; determining the blade vibration frequency according to the time-frequency spectrum diagram; determining a frequency change rate according to the blade vibration frequency and a preset modal frequency; if the frequency change rate is greater than a preset threshold, determining that the engine blade fault information is blade crack information. The actual case of time domain early warning for the rubbing fault based on the tip clearance is as Figure 9 shown. When rubbing occurs, tip clearance - calculating time domain characteristic parameters - time domain abnormal early warning. On the right side, 0 is normal and 1 is abnormal. The appearance of abnormality indicates that there may be a rubbing phenomenon; The actual case of frequency domain diagnosis for the rubbing fault based on the tip clearance is as Figure 10 shown. When judging the abnormal frequency domain, it can be seen that there is a peak cutting phenomenon, which is the characteristic of the rubbing fault.

[0090] In this embodiment, the circumferential displacement signal of the blade is denoted as the original signal x(t), where t represents time. Since the actual signal is often disturbed by noise, preprocessing is required to improve the analysis accuracy.

[0091] The preprocessing process is as follows: adopting the wavelet threshold denoising method, selecting the Symlet wavelet basis function and the decomposition level J, performing discrete wavelet decomposition on x(t), and obtaining the wavelet coefficients as the decomposition scale w j,k , and the translation parameter k. The soft threshold denoising formula applied to the wavelet coefficients is: In the formula, λ is the noise filtering threshold, usually taking σ is the noise standard deviation, and N is the signal length, that is, the number of blade rotation cycles.

[0092] Using the wavelet coefficients for denoising to reconstruct the signal, obtaining the preprocessed original signal x denoised (t), and performing wavelet transform on it: In the formula, a is the scale parameter, which is inversely proportional to the frequency, generally b is the translation parameter, representing the time position, generally taking a value equal to the rotational speed frequency, that is

[0093] Furthermore, by calculating the modulus square |W(a,b)| of the wavelet coefficient W(a,b) 2 , generating a time-frequency spectrum diagram, which is used to reflect the energy distribution of the signal at different times and frequencies. In the time-frequency spectrum diagram, the blade vibration frequency is manifested as a ridge line where the energy is concentrated. Therefore, the blade vibration frequency is obtained by extracting the ridge line. The specific expression is: In the formula, a max (t) is the scale with the maximum energy at time t in the time-frequency spectrum diagram, and f sThe adoption frequency of the single sensor at this moment, which is the rotational frequency.

[0094] Since cracks will cause a decrease in the blade stiffness, resulting in the vibration frequency deviating from the normal modal frequency. Therefore, by comparing the extracted blade vibration frequency with the modal frequency, crack faults can be diagnosed. Specifically, calculate the blade vibration frequency f when there is no fault nolmal and calculate its average frequency Calculate the average frequency of the blade suspected of having a crack fault If the frequency change rate exceeds the empirical value of 2.5%, it can be determined that the blade has a crack.

[0095] It should be noted that the target circumferential displacement signal and the time-series tip clearance signal can be fused to match different fault characteristics, and finally achieve the efficient comprehensive diagnosis and evaluation of various faults of aero-engines.

[0096] The engine fault detection method based on a single sensor proposed in this embodiment obtains the eddy current original signal and the optical fiber pulse signal of the fiber optic eddy current composite sensor; the fiber optic eddy current composite sensor is installed at the position of the aero-engine casing; calculate the blade radial displacement signal according to the eddy current original signal, and calculate the blade circumferential displacement signal according to the optical fiber pulse signal; filter the blade circumferential displacement signal to obtain the target circumferential displacement signal; resample the blade radial displacement signal to obtain the time-series tip clearance signal; determine the engine blade fault information according to the target circumferential displacement signal and the time-series tip clearance signal. In this way, by directly measuring the eddy current original signal and the optical fiber pulse signal reflecting the dynamic characteristics of the blade with a single sensor, the transmission path is shortened, the sensitivity, accuracy and measuring point utilization rate of the diagnosis are improved, the complexity of sensor arrangement is reduced, and it has the advantages of strong real-time performance, high diagnosis accuracy and wide application range. It can be used for the condition monitoring, fault warning and health management of aero-engines, and improve the safety and reliability of engine operation.

[0097] Embodiment 2

[0098] In addition, the present disclosure embodiment provides an engine fault detection device 1100 based on a single sensor. Please refer to Figure 11 and this device includes:

[0099] An acquisition module 1101, configured to acquire the eddy current original signal and the optical fiber pulse signal of the fiber optic eddy current composite sensor; the fiber optic eddy current composite sensor is installed at the position of the aero-engine casing;

[0100] A calculation module 1102, configured to calculate the blade radial displacement signal according to the eddy current original signal, and calculate the blade circumferential displacement signal according to the optical fiber pulse signal;

[0101] A processing module 1103 is configured to filter the circumferential displacement signal of the blade to obtain a target circumferential displacement signal; resample the radial displacement signal of the blade to obtain a time-series tip clearance signal.

[0102] A determination module 1104 is configured to determine engine blade fault information according to the target circumferential displacement signal and the time-series tip clearance signal.

[0103] Optionally, a calculation module 1102 is further configured to filter the eddy current original signal to obtain an eddy current filtered signal; obtain the current speed of the aeroengine and determine the dynamic sensitivity corresponding to the current speed; convert the eddy current filtered signal into the radial displacement signal of the blade according to the dynamic sensitivity; perform a time point number conversion on the fiber optic pulse signal to obtain the measured time point number; determine the time point number difference between the preset theoretical time point number and the measured time point number, and obtain the circumferential displacement signal of the blade according to the product of the time point number difference and the current speed.

[0104] Optionally, the processing module 1103 is further configured to resample the radial displacement signal of the blade to obtain a blade tip clearance value; perform correction compensation on the blade tip clearance value based on a preset static machining dimension of the blade to obtain a corrected blade tip clearance value; perform a traveling wave analysis on the corrected blade tip clearance value to obtain the time-series tip clearance signal.

[0105] Optionally, the determination module 1104 is further configured to obtain a single blade signal according to the target circumferential displacement signal, and obtain the blade phase according to the single blade signal; calculate a coefficient of variation according to the blade phase to obtain a variation characteristic parameter; obtain a phase characteristic evaluation result according to the variation characteristic parameter; obtain an amplitude warning threshold according to the blade phase, and obtain an amplitude characteristic evaluation result according to the amplitude warning threshold and the target circumferential displacement signal; determine that the engine blade fault information is surge information or resonance information or foreign object impact fault information according to the phase characteristic evaluation result and the amplitude characteristic evaluation result.

[0106] Optionally, the determination module 1104 is further configured to fit the time-series tip clearance signal to obtain a radial relative motion state; obtain an unbalance amplitude and an unbalance phase according to the radial relative motion state based on a cross-correlation algorithm; determine that the engine blade fault information is engine unbalance fault information according to the unbalance amplitude and the unbalance phase.

[0107] Optionally, the determination module 1104 is further configured to detect the timing tip clearance signal based on an anomaly judgment algorithm to obtain an anomaly signal; perform time-frequency analysis on the anomaly signal to obtain a time-frequency energy spectrum; if there is a rub feature in the time-frequency energy spectrum, determine that the engine blade fault information is rub fault information.

[0108] Optionally, the determination module 1104 is further configured to perform discrete wavelet decomposition on the blade circumferential displacement signal to obtain wavelet coefficients; calculate the modulus square of the wavelet coefficients, obtain a time-frequency spectrogram according to the modulus square; determine the blade vibration frequency according to the time-frequency spectrogram; determine a frequency change rate according to the blade vibration frequency and a preset modal frequency; if the frequency change rate is greater than a preset threshold, determine that the engine blade fault information is blade crack information.

[0109] The device provided in the embodiments of the present disclosure can execute the steps of the single-sensor-based engine fault detection method provided in Embodiment 1. To avoid repetition, details are not described herein again.

[0110] The single-sensor-based engine fault detection device proposed in this embodiment acquires the eddy current original signal and the optical fiber pulse signal of the fiber optic eddy current composite sensor; the fiber optic eddy current composite sensor is installed at the position of the aero-engine casing; calculates the blade radial displacement signal according to the eddy current original signal, and calculates the blade circumferential displacement signal according to the optical fiber pulse signal; filters the blade circumferential displacement signal to obtain a target circumferential displacement signal; resamples the blade radial displacement signal to obtain a timing tip clearance signal; determines the engine blade fault information according to the target circumferential displacement signal and the timing tip clearance signal. In this way, by directly measuring the eddy current original signal and the optical fiber pulse signal that reflect the dynamic characteristics of the blade with a single sensor, the transmission path is shortened, the sensitivity, accuracy and measuring point utilization rate of diagnosis are improved, the complexity of sensor arrangement is reduced, and it has the advantages of strong real-time performance, high diagnostic accuracy and wide application range. It can be used for the condition monitoring, fault warning and health management of aero-engines, and improve the safety and reliability of engine operation.

[0111] Embodiment 3

[0112] In addition, the embodiments of the present disclosure provide a computer device, including a memory and a processor, where the memory stores a computer program, and when the computer program is executed by the processor, the single-sensor-based engine fault detection method described in Embodiment 1 is implemented.

[0113] The device provided in the embodiments of the present disclosure can execute the steps of the single-sensor-based engine fault detection method provided in Embodiment 1. To avoid repetition, details are not described herein again.

[0114] Embodiment 4

[0115] An embodiment of the present disclosure provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method for detecting engine faults based on a single sensor described in Embodiment 1 herein.

[0116] In this embodiment, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a magnetic disk, an optical disk, or the like.

[0117] The computer-readable storage medium provided in this embodiment can implement the method for detecting engine faults based on a single sensor provided in Embodiment 1. To avoid repetition, it will not be elaborated herein.

[0118] In all the examples shown and described herein, any specific value should be construed as merely exemplary, not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0119] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0120] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and all of these belong to the protection scope of the present invention.

Claims

1. An engine fault detection method based on a single sensor, characterized in that: include: Obtaining the original eddy current signal and the optical fiber pulse signal of the optical fiber eddy current composite sensor; The optical fiber eddy current composite sensor is installed at the casing of the aircraft engine; Calculate the blade radial displacement signal according to the eddy current original signal, and calculate the blade circumferential displacement signal according to the optical fiber pulse signal; Filtering the blade circumferential displacement signal to obtain a target circumferential displacement signal; Resampling the blade radial displacement signal to obtain a time-series blade tip clearance signal; Engine blade fault information is determined according to the target circumferential displacement signal and the sequential blade tip clearance signal.

2. The engine fault detection method based on a single sensor according to claim 1, characterized in that: The step of calculating the blade radial displacement signal according to the eddy current original signal and calculating the blade circumferential displacement signal according to the optical fiber pulse signal comprises: Filtering the eddy current original signal to obtain an eddy current filtered signal; Obtaining a current rotation speed of the aircraft engine, and determining a dynamic sensitivity corresponding to the current rotation speed; Converting the eddy current filter signal into the blade radial displacement signal according to the dynamic sensitivity; Converting the optical fiber pulse signal into time points to obtain measurement time points; The time point difference between the preset theoretical time point number and the measured time point number is determined, and the blade circumferential displacement signal is obtained according to the product of the time point difference and the current rotation speed.

3. The engine fault detection method based on a single sensor according to claim 1, characterized in that: The resampling of the blade radial displacement signal to obtain a time-series blade tip clearance signal includes: Resampling the blade radial displacement signal to obtain a blade tip clearance value; Correcting and compensating the blade tip clearance value based on a preset blade static processing size to obtain a corrected blade tip clearance value; The corrected blade tip clearance value is subjected to traveling wave analysis to obtain the time-series blade tip clearance signal.

4. The engine fault detection method based on a single sensor according to claim 1, characterized in that: Determining engine blade fault information according to the target circumferential displacement signal includes: Obtaining a single blade signal according to the target circumferential displacement signal, and acquiring a blade phase according to the single blade signal; Calculate the coefficient of variation according to the blade phase to obtain a variation characteristic parameter; Obtaining a phase characteristic evaluation result according to the variation characteristic parameter; Obtaining an amplitude warning threshold according to the blade phase, and obtaining an amplitude characteristic evaluation result according to the amplitude warning threshold and the target circumferential displacement signal; The engine blade fault information is determined to be surge information, resonance information, or foreign object strike fault information according to the phase feature evaluation result and the amplitude feature evaluation result.

5. The engine fault detection method based on a single sensor according to claim 1, characterized in that: Determining engine blade fault information according to the sequential blade tip clearance signal includes: Fitting the sequential blade tip clearance signal to obtain a radial relative motion state; Based on a cross-correlation algorithm, an unbalance amplitude and an unbalance phase are obtained according to the radial relative motion state; The engine blade fault information is determined as engine imbalance fault information according to the imbalance amplitude and the imbalance phase.

6. The engine fault detection method based on a single sensor according to claim 1, characterized in that: Determining engine blade fault information according to the sequential blade tip clearance signal includes: Detecting the sequential blade tip clearance signal based on an abnormality judgment algorithm to obtain an abnormal signal; Performing time-frequency analysis on the abnormal signal to obtain a time-frequency energy spectrum; If there is a rubbing feature in the time-frequency energy spectrum, it is determined that the engine blade fault information is rubbing fault information.

7. The engine fault detection method based on a single sensor according to any one of claims 1 to 6, characterized in that: The method further comprises: Performing discrete wavelet decomposition on the blade circumferential displacement signal to obtain wavelet coefficients; Calculating the square of the modulus of the wavelet coefficients, and obtaining a time-frequency spectrum diagram according to the square of the modulus; determining the blade vibration frequency according to the time-frequency spectrum; Determining a frequency change rate according to the blade vibration frequency and a preset modal frequency; If the frequency change rate is greater than a preset threshold, it is determined that the engine blade fault information is blade crack information.

8. An engine fault detection device based on a single sensor, characterized in that: include: An acquisition module is used to acquire the eddy current original signal and the optical fiber pulse signal of the optical fiber eddy current composite sensor; The optical fiber eddy current composite sensor is installed at the casing of the aircraft engine; A calculation module, used for calculating a blade radial displacement signal according to the eddy current original signal, and calculating a blade circumferential displacement signal according to the optical fiber pulse signal; A processing module, used for filtering the blade circumferential displacement signal to obtain a target circumferential displacement signal; Resampling the blade radial displacement signal to obtain a time-series blade tip clearance signal; A determination module is used to determine engine blade fault information based on the target circumferential displacement signal and the sequential blade tip clearance signal.

9. A computer device, characterized in that: The invention comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the engine fault detection method based on a single sensor as claimed in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: It stores a computer program, and when the computer program is executed by a processor, the engine fault detection method based on a single sensor as claimed in any one of claims 1 to 7 is implemented.

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