A method for processing vibration signals onboard a high-bypass-ratio turbofan engine

Abstract

The present invention discloses an onboard vibration signal processing method for a high-bypass ratio turbofan engine, comprising: step 1, monitoring a high-speed gear signal, and calculating a high-speed gear signal period at a current moment according to the speed; step 2, collecting and marking the number of points of the collected vibration signal data in the high-speed gear signal period, and marking the vibration signal within the high-speed gear signal period; step 3, calculating the number of vibration points required for cubic spline interpolation of the collected vibration signal within the high-speed gear signal period according to an A / D sampling frequency and a frequency resolution, and obtaining a sampling point sequence of the vibration signal; step 4, filtering the sampling point sequence of the vibration signal by a low-pass filter to remove high-frequency components, and obtaining a filtered point sequence of the vibration signal after filtering; and step 5, performing cross-correlation processing on the filtered point sequence of the vibration signal, and obtaining the amplitude and phase of the vibration signal within a high-speed gear signal period.

Description

Technical Field

[0001] The present invention relates to, but is not limited to, the technical field of aviation engine vibration monitoring, and in particular to a method for processing airborne vibration signals of a high-bypass-ratio turbofan engine. Background Art

[0002] Vibration signal is one of the important signals reflecting the working status of the engine. It contains a lot of operating status information of the system.

[0003] Currently, vibration signal processing is an effective method for diagnosing aircraft engine faults. Most structural strength faults are closely related to vibration signals. Therefore, engine vibration monitoring is a key component of condition monitoring and fault diagnosis. Sensors can capture various engine vibration signals. By real-time monitoring of parameters such as amplitude, intensity, and phase, combined with the inherent characteristics of vibration signals, engine operation can be monitored in real time to prevent major accidents and losses to the company. Therefore, the spectral information of vibration signals is crucial for understanding the dynamic and fault characteristics of engines. Researching methods for measuring vibration signal frequency is of great engineering significance.

[0004] However, traditional methods for measuring vibration signal frequency typically involve randomly sampling as many vibration signals as possible, then using FFT to convert the signals into the frequency domain and determine their frequencies. When using FFT to perform spectral analysis on a signal, the accuracy of the analysis depends primarily on aliasing, quantization error, spectral leakage, and the picket fence effect. Random sampling of vibration signals involves sampling at equal time intervals, and the resulting discrete signals generally do not meet the requirement for a full period, resulting in significant errors. The presence of spectral leakage and the picket fence effect compromises the accuracy of vibration analysis. Summary of the Invention

[0005] The purpose of the embodiment of the present invention is: the embodiment of the present invention provides an onboard vibration signal processing method for a high bypass ratio turbofan engine, so as to solve the problem in the existing vibration signal processing method that, since the vibration signal is randomly collected in a manner of sampling at equal time intervals, the intercepted discrete signal generally does not meet the full period condition, thereby generating large errors, spectral leakage and fence effect, which affect the accuracy of vibration analysis.

[0006] The technical solution of the embodiment of the present invention is as follows: To address the problems existing in the current method, the embodiment of the present invention provides a method for processing vibration signals onboard a high bypass ratio turbofan engine, comprising:

[0007] Step 1: monitor the high-speed gear signal and calculate the high-speed gear signal period at the current moment according to the speed;

[0008] Step 2: In the high gear signal period, collect and mark the points of the collected vibration signal data, and record the vibration signal in the high gear signal period as V k (n);

[0009] Step 3: Calculate the vibration signal collected in step 2 in the high gear signal period T according to the A / D sampling frequency and frequency resolution. k The number of vibration points required for inner cubic spline interpolation is used to obtain the sampling point sequence x(n) of the vibration signal;

[0010] Step 4: filtering the sampling point sequence of the vibration signal through a low-pass filter to remove high-frequency components, and obtaining a filtered point sequence x'(n) of the vibration signal after filtering;

[0011] Step 5: Perform cross-correlation processing on the filter point sequence x'(n) of the vibration signal to obtain the amplitude and phase of the vibration signal within a high-tooth signal period.

[0012] Optionally, in the above-mentioned high bypass ratio turbofan engine airborne vibration signal processing method, the period T of the high gear signal at the current moment is calculated in step 1. k for:

[0013] T k =t k -t k-1 ;

[0014] Among them, t k is the moment corresponding to the kth rising edge of the high-speed tooth, k=1, 2, ..., n, indicating the sequence number of the rising edge.

[0015] Optionally, in the above-mentioned high bypass ratio turbofan engine airborne vibration signal processing method, in step 2, during the high tooth signal period T k , mark the number of points of the collected vibration signal data, recorded as N k And the vibration signal within the high tooth signal period is recorded as V k (n), t k-1 <t≤t k , n=1,2,…N k .

[0016] Optionally, in the above-mentioned method for processing airborne vibration signals of a high bypass ratio turbofan engine, in step 3,

[0017] The calculated period T of the high tooth signal k The number of vibration points N required for inner cubic spline interpolation is an integer power of 2, and N is less than or equal to N k ; Among them, N k When it is an integer power of 2, N=N k .

[0018] Optionally, in the above-mentioned high bypass ratio turbofan engine airborne vibration signal processing method, step 3 includes:

[0019] For vibration signal V k (t) Perform cubic spline interpolation and find the spline interpolation function x(n):

[0020] x(n)=a i +b i V k (n)+c i V k (n) 2 +d i V k (n) 3 ; n=0,1,…,N k ;

[0021] Among them, the four undetermined parameters are a i ,b i ,c i ,d i ;

[0022] The sampling frequency of each high-tooth signal period is calculated according to the current speed and resampled to obtain the sampling signal x(n).

[0023] Optionally, in the above-mentioned high bypass ratio turbofan engine onboard vibration signal processing method, the manner of performing cross-correlation processing on the filter point sequence x'(n) of the vibration signal in step 5 is:

[0024]

[0025]

[0026] The amplitude is:

[0027] The phase is:

[0028] Optionally, in the above-mentioned high bypass ratio turbofan engine onboard vibration signal processing method,

[0029] Step 6: By looping through steps 1 to 5, the amplitude and phase of the vibration signal within each high-tooth signal period are obtained to measure the frequency of the engine vibration signal.

[0030] Optionally, in the above-mentioned method for processing airborne vibration signals of a high bypass ratio turbofan engine, in step 1, the method for monitoring and calculating the high-speed gear signal is:

[0031] The collected speed pulse signal is judged. When it is judged to be a speed high-tooth signal, the flag is set to 1 and the high-tooth signal period at the current moment is calculated.

[0032] Optionally, in the above-mentioned method for processing vibration signals onboard a high bypass ratio turbofan engine, in step 2, the vibration signals are collected in the following manner:

[0033] When a high-tooth signal is identified, the flag of the vibration signal at this moment is set to 1, and all vibration signals between the current vibration signal with the flag being 1 and the previous vibration signal with the flag being 1 are collected for reconstruction.

[0034] The beneficial effects of the embodiments of the present invention are:

[0035] The embodiment of the present invention provides a method for processing vibration signals onboard a high-bypass-ratio turbofan engine. Specifically, the method adopts a signal reconstruction method, takes the high-speed tooth signal as a reference, synchronously collects vibration signals, and uses the high-speed tooth signal as a period to measure the vibration signal, providing a stable and standard reference source, making the spectrum analysis of the diagnostic signal more stable and accurate. Compared with the method of performing spectrum analysis through a direct FFT algorithm, the present invention adopts a direct labeling method, takes integer multiples of the fundamental frequency period as the sampling time, and combines cubic spline interpolation to re-collect the vibration signal. The technical solution provided by the present invention has the following beneficial effects: First, it overcomes the shortcomings of inaccurate period acquisition and large phase error when predicting the next cycle speed by measuring the past speed; second, it can eliminate or weaken the spectrum leakage and fence effect of non-integer period sampling in spectrum analysis, which is conducive to the accurate analysis of vibration signals; third, because the vibration signal waveform reconstructed by the present invention is smoother and the sampling is more accurate, the method has a strong anti-interference ability; fourth, the amount of computation required for the airborne vibration signal processing method provided by the present invention is very small, the signal reconstruction method is simple and effective, and is particularly suitable for real-time implementation onboard.

[0036] Therefore, the technical solution provided by the embodiment of the present invention can stably and accurately measure the amplitude and phase of the vibration signal in a complex environment with strong vibration and high noise of an aircraft engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0038] Figure 1 A flow chart of a method for processing airborne vibration signals of a high bypass ratio turbofan engine provided by an embodiment of the present invention;

[0039] Figure 2A schematic diagram of a hardware architecture for executing the airborne vibration signal processing method provided in an embodiment of the present invention;

[0040] Figure 3 Flowchart of monitoring and calculating high-speed gear signal in an embodiment of the present invention;

[0041] Figure 4 Flowchart of collecting vibration signals in an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the principle of calculating the high-speed gear signal period at the current moment in a specific embodiment of the present invention;

[0043] Figure 6 Schematic diagram of the waveform of the high-speed gear signal collected in a specific embodiment of the present invention;

[0044] Figure 7 A schematic diagram of a vibration signal waveform in a specific embodiment of the present invention;

[0045] Figure 8 It is the amplitude spectrum of the vibration signal after Fourier transformation in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0046] To make the purpose, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other in any manner.

[0047] The above background has already explained that in the existing vibration signal processing method, since the random collection method of vibration signals is sampling at equal time intervals, the intercepted discrete signals generally do not meet the full cycle condition, which will produce large errors, spectral leakage and fence effects, affecting the accuracy of vibration analysis.

[0048] To address the issues with the aforementioned vibration signal processing method, an improved approach is to first use the engine speed signal as a reference signal, selecting a sampling time that is an integer multiple of the high-speed gear signal period (for details on the high-speed gear signal, see "A Method, Device, and Circuit for Determining an Engine Rotor Phase Reference"). Cubic spline interpolation is then performed on the sampled data to fit the original vibration signal. The restored vibration signal is then sampled. Finally, an FFT operation is performed on the sampled signal to determine the signal's frequency. This method effectively overcomes issues such as spectral leakage and the picket fence effect.

[0049] However, the improved FFT method has many problems. A more mature method is the "time domain full-cycle synchronous average correlation method". Specifically, the cross-correlation algorithm expressed as follows (see the paper: Kang Chengliang, Zeng Sheng, Zhao Liangliang. "Design and Implementation of Multi-machine Communication in Fully Automatic Balancing Machine Control System") is used to calculate the amplitude and phase of the vibration signal. This algorithm can also be regarded as an ultra-narrow bandpass filter that can filter out most signals other than the power frequency: Where: M is the number of sampling points in the entire cycle, and x(i) is the collected vibration data. From this, the amplitude information of the vibration center component can be calculated: amplitude This method is also called the "correlation method". It can obtain the amplitude information of the vibration signal with high precision and has a small amount of calculation. It is particularly suitable for airborne computers. The main disadvantage is that it requires the speed signal to be very stable. In existing methods, the spectrum leakage problem is generally solved by changing the sampling rate in real time or by windowing and other methods. The method of changing the sampling rate in real time is achieved by controlling the actual sampling rate through the speed information. It is a dynamic balancing process with limited accuracy. The windowing method is relatively easy to implement, but the windowing method is based on the truncation of the signal, and each window function has different advantages and disadvantages. The selection of which window function is generally based on experience, so the actual effect is not ideal. Therefore, there is an urgent need to provide an airborne vibration signal amplitude and phase detection method that requires simple calculation, high reliability and can ensure conditioning accuracy. The present invention provides an airborne vibration signal processing method for a large bypass ratio turbofan engine in response to this demand.

[0050] The present invention provides the following specific embodiments that can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0051] In order to solve the problems existing in the current methods, the present invention proposes a method for processing vibration signals onboard a high bypass ratio turbofan engine. Figure 1 A flowchart of a method for processing airborne vibration signals of a high bypass ratio turbofan engine provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the hardware architecture for executing the airborne vibration signal processing method provided in an embodiment of the present invention. The method provided in an embodiment of the present invention is simple in design, easy to implement, has strong anti-interference capability, and can effectively improve the vibration amplitude and phase acquisition accuracy.

[0052] To achieve the above object, the airborne vibration signal processing method provided by the embodiment of the present invention includes the following steps:

[0053] Step 1: Monitor the high-speed gear signal and calculate the period T of the high-speed gear signal at the current moment according to the speed. k ;

[0054] In step 1, calculate the period T of the high gear signal at the current momentk The way is:

[0055] T k =t k -t k-1 ;

[0056] Among them, t k is the moment corresponding to the kth rising edge of the high-speed tooth, k=1, 2, ..., n, indicating the sequence number of the rising edge.

[0057] Step 2: In the high gear signal period T k , collect and mark the number of points of the collected vibration signal data, the number of points is recorded as N k And the vibration signal within the high tooth signal period is recorded as V k (n), where t k-1 <t≤t k , n=1,2,…N k .

[0058] Step 3: Calculate the vibration signal collected in step 2 in the high gear signal period T according to the A / D sampling frequency and frequency resolution. k The number of vibration points N required for inner cubic spline interpolation is used to obtain the sampling point sequence x(n) of the vibration signal.

[0059] In step 3, N is an integer power of 2 and N is less than N k .

[0060] For example, N is typically 16 or 32.

[0061] Step 4: filtering the sampling point sequence of the vibration signal through a low-pass filter to remove high-frequency components, and obtaining a filtered point sequence x'(n) of the vibration signal after filtering;

[0062] Step 5: Perform cross-correlation processing on the filter point sequence x'(n) of the vibration signal to obtain the amplitude and phase of the vibration signal within a high-tooth signal period.

[0063] In one implementation of the embodiment of the present invention, Figure 3 As shown, this is a flow chart of monitoring and calculating the high-speed tooth signal in an embodiment of the present invention.

[0064] In step 1 of the embodiment of the present invention, the collected speed pulse signal is judged, and when it is judged to be a speed high-tooth signal, the flag is set to 1, and then the high-tooth signal period at the current moment is calculated.

[0065] In one implementation of the embodiment of the present invention, Figure 4 As shown in FIG. 1 , a flow chart of collecting vibration signals in an embodiment of the present invention.

[0066] When a high-tooth signal is identified, the flag of the vibration signal at this moment is set to 1, and all vibration signals between the current vibration signal with the flag being 1 and the previous vibration signal with the flag being 1 are collected for reconstruction.

[0067] In fact, that is, when two adjacent flag bits of the vibration signal are monitored to be 1, the vibration signal with the adjacent flag bit being 1 is taken to reconstruct the vibration signal; while collecting the speed pulse signal, the vibration signal is collected, and when the high-tooth signal is identified, the vibration signal flag bit at this moment is set to 1. Since the high-tooth signal is a periodic signal, the vibration signal flag bit being 1 is also a periodic signal; when a vibration signal with a flag bit being 1 is monitored, all vibration signals between the vibration signal with the current flag bit being 1 and the vibration signal with the previous flag bit being 1 are reconstructed.

[0068] In one implementation of the embodiment of the present invention, the specific implementation process of step 3 may include:

[0069] For vibration signal V k (t) Perform cubic spline interpolation and find the spline interpolation function x(n):

[0070] x(n)=a i +b i V k (n)+c i V k (n) 2 +d i V k (n) 3 ; n=0,1,…,N k ;

[0071] The four unknown parameters in the above formula are a i ,b i ,c i ,d i ;.

[0072] The sampling frequency of each cycle is calculated according to the current speed and resampled to obtain the sampling signal x(n).

[0073] In one implementation of the embodiment of the present invention, the cross-correlation processing of the filter point sequence x'(n) of the vibration signal in step 5 may be performed in the following manner:

[0074]

[0075] The specific calculated amplitude is:

[0076] The specific calculated phase is:

[0077] Furthermore, the method provided by the embodiment of the present invention may also include:

[0078] Step 6, by cyclically executing steps 1 to 5, the amplitude and phase of the vibration signal in each high-tooth signal period are obtained, thereby measuring the frequency of the engine vibration signal and thus measuring the frequency of the engine vibration signal.

[0079] The embodiment of the present invention provides an onboard vibration signal processing method for a high-bypass turbofan engine. Specifically, the method adopts a signal reconstruction method, takes the high-speed tooth signal as a reference, synchronously collects the vibration signal, and uses the high-speed tooth signal as a periodic measurement method to provide a stable and standard reference source, making the spectrum analysis of the diagnostic signal more stable and accurate. Compared with the method of performing spectrum analysis through a direct FFT algorithm, the present invention adopts a direct labeling method, takes integer multiples of the fundamental frequency period as the sampling time, and combines cubic spline interpolation to re-collect the vibration signal. The technical solution provided by the present invention has the following beneficial effects: First, it overcomes the shortcomings of inaccurate period acquisition and large phase error when predicting the next cycle speed by measuring the past speed; second, it can eliminate or weaken the spectrum leakage and fence effect of non-integer period sampling in spectrum analysis, which is conducive to the accurate analysis of vibration signals; third, because the vibration signal waveform reconstructed by the present invention is smoother and the sampling is more accurate, the method has a strong anti-interference ability; fourth, the amount of computation required for the onboard vibration signal processing method provided by the present invention is very small, the signal reconstruction method is simple and effective, and is particularly suitable for real-time implementation on airborne.

[0080] Therefore, the technical solution provided by the embodiment of the present invention can stably and accurately measure the amplitude and phase of the vibration signal in a complex environment with strong vibration and high noise of an aircraft engine.

[0081] The following is a schematic illustration of the specific implementation of the high bypass ratio turbofan engine airborne vibration signal processing method provided by the embodiment of the present invention through some specific implementation examples.

[0082] Please also see Figures 1 to 8 .

[0083] The application environment of this specific embodiment is as follows Figure 2 As shown. Figure 3 and Figure 4 The vibration signal frequency calculation method in this specific embodiment includes the following steps:

[0084] (1) Monitor the high-speed gear signal and calculate the period T of the high-speed gear signal at the current moment according to the speed k , by the following formula:

[0085] T k =t k -t k-1

[0086] Calculate T k Among them, t k is the time corresponding to the kth rising edge of the high-speed gear, k=1,2,...,n, indicating the sequence number of the rising edge. Figure 5 FIG. 1 is a schematic diagram showing the principle of calculating the high-speed tooth signal period at the current moment in a specific embodiment of the present invention.

[0087] (2) In the high tooth signal period T k , collect and mark the number of points of the collected vibration signal data, recorded as N k And the vibration signal in this period is recorded as V k (n), t k-1 <t≤t k , n=1,2,…N k .

[0088] (3) Calculate the high-tooth signal period T according to the A / D sampling frequency and frequency resolution k The number of vibration points N required for inner cubic spline interpolation is an integer power of 2 and N is less than N k , N is generally 16 or 32.

[0089] In step (3), the vibration signal V k (t) Perform cubic spline interpolation and find the spline interpolation function x(n) as follows:

[0090] x(n)=a i +b i V k (n)+c i V k (n) 2 +d i V k (n) 3 ; n=0,1,…,N k ;

[0091] Among them, the four undetermined parameters a i ,b i ,c i ,d i The sampling frequency of each cycle is calculated according to the current speed and resampled to obtain the sampling signal x(n).

[0092] (4) The high-frequency components are filtered out by a low-pass filter, and the filtered signal is recorded as x'(n).

[0093] (5) Perform correlation calculation on the vibration signal x'(n) to obtain the amplitude and phase of the vibration signal.

[0094] (6) Execute steps (1) to (5) repeatedly to measure the frequency of the engine vibration signal.

[0095] The effects of the present invention can be further illustrated by the following examples:

[0096] The data of the high-speed gear signal and the vibration signal are synchronously sampled at equal time intervals, such as Figure 1 The selection of engine speed, sampling rate and number of sampling points is shown in Table 1.

[0097] Table 1 Comparison of speed, sampling rate and number of sampling points

[0098]

[0099] The sampling frequency is set to 40000Hz, the speed is 3000r / min, and it is in the speed-up stage. The number of rotor teeth M = 30, B = 10%. Figure 6 The figure shows a waveform diagram of the speed high-tooth signal collected in a specific embodiment of the present invention. The large-scale repeated waveform in the figure represents the output signal of the speed sensor, the light gray waveform represents the waveform range generated by the high-tooth, and the waveform in the middle represents the high-tooth signal period (t k-1 ,t k ).

[0100] The high gear signal period can be obtained from the speed: T k =0.02;

[0101] N k =f s *T k =10000*0.02=200;

[0102] The data length of the vibration signal is set to 3200 points and the number of cycles is 16. Figure 7 is a schematic diagram of a vibration signal waveform in a specific embodiment of the present invention, Figure 8 It is the amplitude spectrum of the vibration signal after Fourier transformation in a specific embodiment of the present invention.

[0103] According to the identified period start and end points (t k-1 ,t k ), perform full-cycle resampling through cubic spline interpolation in step 4, and Figure 7 The vibration signal in the adjacent period starts and ends at equal intervals and 32 points are collected. A total of 4 periods are collected, so a total of 32*4=128 points are collected.

[0104] Then, through the filtering process in step 4 and the correlation calculation of the processed data, it can be seen that the high-frequency noise has been filtered out, the vibration signal spectrum is clear, and the signal is prominent. Therefore, the measurement results of this method are stable.

[0105] The methods for processing airborne vibration signals of high-bypass-ratio turbofan engines provided in various embodiments of the present invention mainly solve the problems of aliasing effect, quantization error, spectrum leakage and fence effect in the existing technology for spectrum analysis of aircraft engine vibration signals. The signal processing method provided by Shaolin Temple of the present invention, based on the analysis of speed signal and vibration signal, uses the period of high-speed tooth signal (in the rotor sound wheel signal extracted by the speed sensor, the output signal amplitude of one tooth is higher than that of other teeth, and the tooth is called high-tooth signal) as the reference to mark the vibration signal, and performs spectrum analysis on the marked signal. The present invention has the advantages of strong real-time performance, small amount of calculation and high spectrum analysis accuracy, and is particularly suitable for spectrum analysis and processing of airborne vibration signals of aircraft engines in airborne electronic environments.

[0106] In summary, the present invention fully considers the practical application problems of aircraft engine vibration signal processing. According to the characteristics of the speed signal and the vibration signal, the speed high gear signal is used as a reference signal to collect the vibration signal. The obtained result is not only precise but also very accurate.

[0107] Although the embodiments disclosed herein are as described above, the contents are merely embodiments for facilitating understanding of the present invention and are not intended to limit the present invention. Any person skilled in the art may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope of the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A method for processing vibration signals onboard a high bypass ratio turbofan engine, characterized in that: include: Step 1: monitor the high-speed gear signal and calculate the high-speed gear signal period at the current moment according to the speed; Step 2: In the high gear signal period, collect and mark the points of the collected vibration signal data, and record the vibration signal in the high gear signal period as ; Step 3: Calculate the period of the vibration signal collected in step 2 in the high gear signal according to the A / D sampling frequency and frequency resolution. The number of vibration points required for inner cubic spline interpolation is used to obtain the sampling point sequence x(n) of the vibration signal; Step 4: filtering the sampling point sequence of the vibration signal through a low-pass filter to remove high-frequency components, and obtaining a filtered point sequence x'(n) of the vibration signal after filtering; Step 5: Perform cross-correlation processing on the filter point sequence x'(n) of the vibration signal to obtain the amplitude and phase of the vibration signal within a high-tooth signal period; Wherein, the cycle of the high gear signal at the current moment is calculated in step 1 for: ； in, is the time corresponding to the kth rising edge of the high-speed tooth, , indicating the sequence number of the rising edge; In step 2, during the high tooth signal period , marking the number of points of the collected vibration signal data, recorded as , and the vibration signal within the high-tooth signal period is recorded as , , n = 1,2,… ; The method of monitoring the high-speed gear signal in step 1 and collecting the vibration signal in the high-speed gear signal period in step 2 is: While collecting the speed pulse signal, the vibration signal is collected, and when the high tooth signal is identified, the vibration signal flag at this moment is set to 1. Since the high tooth signal is a periodic signal, the vibration signal flag bit is 1 and it is also a periodic signal. When the vibration signal with the flag bit of 1 is monitored, all vibration signals between the vibration signal with the flag bit of 1 and the vibration signal with the previous flag bit of 1 are collected; In step 3, the calculated period of the high tooth signal The number of vibration points N required for inner cubic spline interpolation is an integer power of 2, and N is less than or equal to ;in, When N is an integer power of 2, ; The step 3 includes: Vibration signal Perform cubic spline interpolation and find the spline interpolation function x(n): ；n=0,1,…, ； Among them, the four undetermined parameters are , , , ; The sampling frequency of each high-tooth signal period is calculated according to the current speed and resampled to obtain the sampling signal x(n).

2. The high bypass ratio turbofan engine airborne vibration signal processing method according to claim 1, characterized in that: The method of performing cross-correlation processing on the filter point sequence x'(n) of the vibration signal in step 5 is as follows: ； The amplitude is: ; The phase is: .

3. The method for processing vibration signals onboard a high bypass ratio turbofan engine according to any one of claims 1 to 2, characterized in that: Step 6: By looping through steps 1 to 5, the amplitude and phase of the vibration signal in each high-tooth signal cycle are obtained to measure the frequency of the engine vibration signal.

4. The method for processing vibration signals onboard a high bypass ratio turbofan engine according to any one of claims 1 to 2, characterized in that: In step 1, the method of monitoring and calculating the high-speed gear signal is as follows: The collected speed pulse signal is judged. When it is judged to be a speed high-tooth signal, the flag is set to 1 and the high-tooth signal period at the current moment is calculated.

5. The high bypass ratio turbofan engine airborne vibration signal processing method according to claim 4, characterized in that: In step 2, the vibration signal is collected in the following manner: When a high-tooth signal is identified, the flag of the vibration signal at this moment is set to 1, and all vibration signals between the current vibration signal with the flag being 1 and the previous vibration signal with the flag being 1 are collected for reconstruction.

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