Rotor radial crack fault identification method and identification system based on vibration signal

Abstract

The present invention discloses a rotor radial crack fault identification method and identification system based on vibration signals, including: S1: performing at least Nc vibration tests on the rotor, obtaining each vibration signal, and performing spectrum analysis on each vibration signal to obtain a reference value; S2: performing the Nc+Mth vibration test on the rotor, obtaining the current vibration signal, and performing spectrum analysis on the current vibration signal, and obtaining the current calculated value according to the current spectrum analysis result; S3: obtaining the current fault index Kc and crack index according to the reference value and the current calculated value; S4: judging the current fault type according to the current fault index Kc, and judging the current crack type according to the current fault type and the current crack index. The present invention can effectively identify the rotor radial crack fault through the fault index and the crack index, and timely discover the early signs of the rotor crack, thereby providing a basis for eliminating the corresponding fault and improving the safety of the engine.

Description

Technical Field

[0001] The present invention relates to the technical field of crack fault identification methods, and in particular to a rotor radial crack fault identification method and an identification system based on vibration signals. Background Art

[0002] During the operation of aircraft engines, the rotor may crack due to long-term operation at high speed, high temperature and torque. In particular, defects such as knife marks and metal inclusions on the shaft increase the possibility of cracks. The strength of the shaft is very important to the safety of the entire engine and aircraft. Once cracks appear on the rotor shaft, the engine is in a dangerous state. The cracks on the shaft may accelerate and cause the shaft to break, resulting in serious consequences. Therefore, the identification of rotor shaft cracks is crucial to ensure the safety of the engine.

[0003] Although many methods have been developed in the traditional research on crack identification based on structural vibration, these methods are difficult to apply to the identification of radial crack faults in aircraft engine rotors due to the complexity and uncertainty of actual engineering. Summary of the invention

[0004] To this end, the present invention provides a rotor radial crack fault identification method and identification system based on vibration signals. The method and system provided by the present invention can effectively identify rotor radial crack faults and promptly discover early signs of rotor cracks, thereby providing a basis for eliminating corresponding faults, improving the safety of the engine, and overcoming the defects of the prior art.

[0005] In order to solve the above technical problems, the present invention provides a rotor radial crack fault identification method based on vibration signals, comprising:

[0006] S1: Perform at least Nc vibration tests on the rotor, obtain the vibration signal each time, and perform spectrum analysis on the vibration signal each time, obtain the measured values ​​F1, F2, U1, U2, U3 according to the spectrum analysis results each time, and then obtain the calculated values ​​Rc, R1, R2, R3, and obtain the reference values ​​Rca, R1a, R2a, R3a according to the calculated values ​​Rc, R1, R2, R3 of the previous Nc times;

[0007] Wherein, Rc is the ratio of the critical speed F1 of the first-order vibration to the critical speed F2 of the second-order vibration, R1 is the rate of change of the first-order critical speed, R2 is the ratio of the 1-fold vibration amplitude U1 to the 2-fold vibration amplitude U2, R3 is the ratio of the 1-fold vibration amplitude U1 to the 3-fold vibration amplitude U3, Rca is the average value of Rc in the previous Nc tests, R1a is the average value of R1 in the previous Nc tests, R2a is the average value of R2 in the previous Nc tests, and R3a is the average value of R3 in the previous Nc tests;

[0008] S2: Conduct the (Nc + M)-th vibration test on the rotor to obtain the current vibration signal, perform spectral analysis on the current vibration signal, and obtain the current Rc, R1, R2, and R3 based on the current spectral analysis results.

[0009] S3: Obtain the current fault index Kc based on the reference value Rca and the current Rc, where Kc = |Rc - Rca| / Rc.

[0010] Obtain the current crack index based on the reference values R1a, R2a, and R3a and the current R1, R2, and R3. The crack index includes a first index and a second index. The first index is R1 < R1a, and the second index is R2 > R2a or R3 > R3a.

[0011] S4: Judge the current fault type based on the current fault index Kc, and judge the current crack type based on the current fault type and the current crack index.

[0012] As a preferred embodiment of the present invention, judging the current fault type based on the current fault index Kc includes:

[0013] If the fault type has not been obtained before the current test, compare the current fault index Kc with e1. If Kc < e1, judge that the current fault type is no fault. Here, the value range of e1 is 0.02 - 0.08.

[0014] If the fault type has been obtained before the current test, judge the current fault type based on the fault type before the current test and the current fault index Kc.

[0015] As a preferred embodiment of the present invention, judging the current fault type based on the fault type before the current test and the current fault index Kc includes:

[0016] If the result of no fault has been obtained in the vibration test before the current test and the current fault index Kc > e1, compare the current Rc with e2. If |Rc - 1| < e2, judge that the current fault type is a first-level fault. Here, the value range of e2 is 0.02 - 0.05.

[0017] If the result of a first-level fault has been obtained in the vibration test before the current test, compare the current fault index Kc with e3 and e4. If |Rc - 1| > e3 and |Rc - 1| < e4, judge that the current fault type is a second-level fault. Here, the value range of e3 is 0.06 - 0.10, and the value range of e4 is 0.15 - 0.20.

[0018] If the result of the fault type being a level 2 fault has been obtained in the vibration test before the current test, the current Rc is compared with e4. If |Rc-1|>e4, the current fault type is determined to be a level 3 fault.

[0019] As a preferred embodiment of the present invention, judging the current crack type according to the current fault type and the current crack index includes:

[0020] If the current fault type is no fault, the crack type is judged to be no crack;

[0021] If the current fault type is a primary fault, the crack type is determined to be a primary crack;

[0022] If the current fault type is a level 2 fault or a level 3 fault, and any one of the first indicator and the second indicator is met, the crack type is determined to be a level 2 crack;

[0023] If the current fault type is a level 2 fault or a level 3 fault, and the first indicator and the second indicator are both met, then the crack type is determined to be a level 3 crack.

[0024] As a preferred embodiment of the present invention, Rc=F2 / F1, where F1 and F2 are obtained from spectrum analysis results.

[0025] As a preferred embodiment of the present invention, R1=F1 / Fa, where Fa is the average value of the critical speed F1 of the first-order vibration.

[0026] As a preferred embodiment of the present invention, R2=U2 / U1, and U1 and U2 are obtained from spectrum analysis results.

[0027] As a preferred embodiment of the present invention, R3=U3 / U1, where U3 is obtained from the spectrum analysis result.

[0028] As a preferred embodiment of the present invention, Nc is not less than 10.

[0029] A rotor radial crack fault identification system based on vibration signals, using any of the above-mentioned rotor radial crack fault identification methods based on vibration signals, comprises:

[0030] A vibration test module, used for performing several vibration tests on the rotor, wherein the several vibration tests include historical vibration tests and current vibration tests;

[0031] A spectrum analysis module is connected to the vibration test module and is used to obtain a vibration signal obtained by the vibration test and perform spectrum analysis on the vibration signal;

[0032] A data processing module is connected to the spectrum analysis module to obtain spectrum analysis results, obtain measurement values, obtain calculation values ​​based on the measurement values, and obtain reference values ​​based on the calculation values ​​of historical vibration tests;

[0033] The fault judgment module is connected to the data processing module, obtains the current fault index and crack index according to the calculated value and reference value of the current vibration test, judges the current fault type according to the current fault index, and judges the current crack type according to the current fault type and the current crack index.

[0034] The above technical solution of the present invention has the following advantages compared with the prior art:

[0035] The vibration signal-based rotor radial crack fault identification method and identification system described in the present invention can effectively identify rotor radial crack faults through fault indicators and crack indicators, and promptly discover early signs of rotor cracks, thereby providing a basis for eliminating corresponding faults and improving the safety of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0037] Figure 1 It is a flow chart of the rotor radial crack fault identification method based on vibration signals of the present invention.

[0038] Figure 2 It is a schematic diagram of the radial crack of the rotor of the present invention.

[0039] Figure 3 It is a schematic cross-sectional diagram of a radial crack of a rotor according to the present invention.

[0040] Figure 4 It is a schematic diagram of a single-peak spectrum before the radial crack of the rotor is formed in the present invention.

[0041] Figure 5 It is a schematic diagram of the double-peak spectrum after the rotor radial crack is formed in the present invention.

[0042] Figure 6 It is a schematic diagram of the frequency spectrum of the rotor of the present invention with increased harmonic components. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0044] In the description of the present invention, it should be understood that the term "comprising" is intended to cover non-exclusive inclusions, such as a process, method, system, product or apparatus comprising a series of steps or units, which is not limited to the listed steps or units but optionally also includes unlisted steps or units, or optionally also includes other steps or units inherent to these processes, methods, products or apparatuses.

[0045] Embodiment 1

[0046] Reference Figures 1 to 6 As shown, the rotor radial crack fault identification method based on vibration signals of the present invention comprises:

[0047] Reference Figure 2 The figure shows the schematic diagram of the radial crack of the shaft. Figure 3 The figure shows a schematic diagram of a crack cross section. When such a crack appears on the rotor shaft of an aircraft engine, it is like having a very narrow transverse groove. When the rotor rotates, the crack will open and close, and the stiffness near the crack will fluctuate, and its vibration frequency will also change accordingly.

[0048] Reference Figure 3 As shown in the figure, due to the appearance of cracks, the size of the rotor in the y direction is reduced, so the stiffness becomes smaller and its minimum critical speed will also decrease accordingly.

[0049] Newly machined rotor shafts generally do not have cracks, or the cracks are so small that their effects can be ignored. Figure 3 As shown in the figure, the crack depth H is close to 0. When there is no crack, the stiffness of the rotor shaft at this location is isotropic. Figure 4 As shown, when there is no crack, the amplitude is a single peak and the noise is small.

[0050] When the crack depth H is greater than 0 and gradually increases, the stiffness anisotropy of the rotor shaft at the crack appears and increases. Figure 5 As shown, originally attached Figure 4 The single peak of the crack gradually decomposes into two waves, and there are two peaks. When the crack develops further, there will even be three peaks and gradually separate, that is, in addition to the first-order vibration, there are also second-order vibration and third-order vibration. At the beginning, these frequencies are relatively close, and then the gap widens. In addition, refer to the attached Figure 6 As shown, the 2 times frequency (i.e. 2 times the rotation speed frequency) and 3 times frequency (i.e. 3 times the rotation speed frequency) components also increase accordingly, where x is the frequency multiplication.

[0051] The vibration signal contains rich information. A vibration fault may reflect one or more vibration characteristics, so the rotor fault can be judged based on the one or more vibration characteristics.

[0052] Reference Figure 1As shown in the figure, the steps to determine whether the rotor is faulty and the probability of the existence of cracks are as follows:

[0053] S1: Conduct at least Nc vibration tests on the rotor, obtain the vibration signal each time, and perform spectral analysis on the vibration signal each time. Obtain the measured values F1, F2, U1, U2, U3 according to the spectral analysis results each time, and then obtain the calculated values Rc, R1, R2, R3. And obtain the reference values Rca, R1a, R2a, R3a according to the calculated values Rc, R1, R2, R3 of the previous Nc times.

[0054] Among them, Rc is the ratio of the critical speed F1 of the first-order vibration to the critical speed F2 of the second-order vibration, Rc = F2 / F1, and F1 and F2 are obtained from the spectral analysis results. R1 is the change rate of the first-order critical speed, R1 = F1 / Fa, and Fa is the average value of the critical speed F1 of the first-order vibration. R2 is the ratio of the vibration amplitude U1 of the 1x frequency to the vibration amplitude U2 of the 2x frequency, R2 = U2 / U1, and U1 and U2 are obtained from the spectral analysis results. R3 is the ratio of the vibration amplitude U1 of the 1x frequency to the vibration amplitude U3 of the 3x frequency, R3 = U3 / U1, and U3 is obtained from the spectral analysis results. Rca is the average value of Rc in the previous Nc tests. R1a is the average value of R1 in the previous Nc tests. R2a is the average value of R2 in the previous Nc tests, and R3a is the average value of R3 in the previous Nc tests. Nc is the number of tests, Nc is not less than 10, and preferably 10.

[0055] S2: Conduct the (Nc + M)th vibration test on the rotor, obtain the current vibration signal, and perform spectral analysis on the current vibration signal. Obtain the current Rc, R1, R2, R3 according to the current spectral analysis results. Among them, M is a positive integer.

[0056] S3: Obtain the current fault index Kc according to the reference value Rca and the current Rc, Kc = |Rc - Rca| / Rc.

[0057] Obtain the current crack index according to the reference values R1a, R2a, R3a and the current R1, R2, R3. The crack index includes a first index and a second index. The first index is R1 < R1a, and the second index is R2 > R2a or R3 > R3a.

[0058] S4: Judge the current fault type according to the current fault index Kc, and judge the current crack type according to the current fault type and the current crack index.

[0059] Specifically, in step S1, conduct no less than Nc tests on the rotor to be measured, and obtain each reference value Rca, R1a, R2a, R3a according to the data obtained from the Nc tests.

[0060] The spectrum analysis used is the existing spectrum analysis technology in this field. The required first-order vibration critical speed F1, second-order vibration critical speed F2, 1st-order vibration amplitude U1, 2nd-order vibration amplitude U2, and 3rd-order vibration amplitude U3 are obtained through the spectrum analysis of the existing technology.

[0061] In step S2, after the Ncth test, the rotor under test is tested again, i.e., the Nc+Mth test, to obtain the critical speed F1 of the first-order vibration, the critical speed F2 of the second-order vibration, the 1st-order vibration amplitude U1, the 2nd-order vibration amplitude U2, and the 3rd-order vibration amplitude U3 obtained in the Nc+Mth test, i.e., the current test, and calculate Rc, R1, R2, and R3 of that time based on the measured values ​​of that time.

[0062] Rc can be used to determine the possibility of cracks. Perform spectrum analysis on the vibration signal. The lowest frequency is the critical speed F1 of the first-order vibration, followed by the critical speed F2 of the second-order vibration. Figure 4 , 6 It can be seen that when there is no crack in the rotor, there is a single peak without bifurcation, which means that Rc is much greater than 1. Figure 5 It can be seen that when a crack occurs, the single peak bifurcates into multiple peaks (2 peaks or 3 peaks), which means that Rc is relatively close to 1. Analyzing historical data, if Rc is large at the beginning (single peak is not bifurcated) and then Rc is close to 1 (bifurcated), it can be preliminarily judged that a crack has occurred. If Rc gradually increases afterwards, the possibility of crack occurrence increases.

[0063] R1 can be used to judge the rotor crack fault. As mentioned above, the appearance of cracks reduces the size in the y direction, resulting in a decrease in the first-order vibration critical speed. Assume that the average value of the first-order vibration critical speed obtained by the rotor in the previous Nc (for example, Nc = 10) operations is Fa and is set as the first-order vibration critical speed reference value. The current first-order vibration critical speed is F1, then R1 can be obtained. If R1 becomes smaller, a rotor crack fault may have occurred.

[0064] R2 and R3 can be used to determine the occurrence of a fault. For R2 and R3, the vibration signal is spectrally analyzed, each peak is searched and compared with the speed frequency to obtain the 1-fold amplitude U1, 2-fold amplitude U2 and 3-fold amplitude U3, and R2 and R3 are obtained by calculation. The increase of the 2-fold and 3-fold frequency components is also a fault characteristic of rotor cracks, so the two ratios of R2 and R3 can be used as indicators to determine the occurrence of faults.

[0065] In step S3, the calculated values ​​Rc, R1, R2, R3 obtained from the current test are combined with the reference values ​​Rca, R1a, R2a, R3a obtained from the previous Nc tests to obtain the current fault index Kc and the current crack index.

[0066] In step S4, first determine the current fault type based on the current fault index Kc, and then determine the current crack type based on the current fault type and the current crack index, that is, obtain two results: the fault type and the crack type. The fault type is used to indicate whether there is a fault in the current rotor test and the degree of the fault, and the crack type is used to indicate whether there is a crack in the current rotor test and the degree of the crack.

[0067] The determination of the current fault type according to the current fault index Kc mentioned in step S4 specifically includes:

[0068] If the fault type has not been obtained before the current test, then compare the current fault index Kc with e1. If Kc < e1, it is determined that the current fault type is no fault. Here, e1 is a positive number less than 1. The value range of e1 is 0.02 - 0.08, and the optimal value is e1 = 0.03.

[0069] If the fault type has been obtained before the current test, then determine the current fault type according to the fault type before the current test and the current fault index Kc.

[0070] The determination of the current fault type according to the fault type before the current test and the current fault index Kc mentioned above specifically includes:

[0071] If the result of no fault has been obtained for the fault type in the vibration test before the current test, and the current fault index Kc > e1, then compare the current Rc with e2. If |Rc - 1| < e2, it is determined that the current fault type is a first-level fault. Here, e2 < e1. The value range of e2 is 0.02 - 0.05, and the optimal value is e2 = 0.025.

[0072] If the result of a first-level fault has been obtained for the fault type in the vibration test before the current test, then compare the current fault index Kc with e3 and e4. If |Rc - 1| > e3 and |Rc - 1| < e4, it is determined that the current fault type is a second-level fault. The value range of e3 is 0.06 - 0.10, and the optimal value is e3 = 0.08. The value range of e4 is 0.15 - 0.20, and the optimal value is e4 = 0.18.

[0073] If the result of a second-level fault has been obtained for the fault type in the vibration test before the current test, then compare the current Rc with e4. If |Rc - 1| > e4, it is determined that the current fault type is a third-level fault.

[0074] Specifically, the fault types include four levels: no fault, primary fault, secondary fault, and tertiary fault. No fault means no crack fault. Primary fault means a slight fault. Secondary fault means a moderate fault. Third fault means a severe fault. When the rotor is subjected to the initial vibration test, the fault type is no fault.

[0075] If the fault type is not obtained in the vibration test before the Nc+M tests, the fault index Kc of the current test is directly compared with e1.

[0076] If the vibration test before the Nc+Mth test has obtained a specific fault type, the fault type of the current time is determined according to the historical fault type obtained in the vibration test before the Nc+Mth test and the fault index Kc of the current time. If the vibration test before the Nc+Mth test obtains multiple historical fault types, the fault type of the current time is determined according to the fault type obtained for the last time.

[0077] The step S4 of determining the current crack type according to the current fault type and the current crack index specifically includes:

[0078] If the current fault type is no fault, the crack type is determined to be no crack.

[0079] If the current fault type is a primary fault, the crack type is determined to be a primary crack.

[0080] If the current fault type is a level 2 fault or a level 3 fault, and either the first indicator or the second indicator is met, then the crack type is determined to be a level 2 crack.

[0081] If the current fault type is a level 2 fault or a level 3 fault, and the first indicator and the second indicator are both met, then the crack type is determined to be a level 3 crack.

[0082] Specifically, the crack types include four levels: no crack, primary crack, secondary crack, and tertiary crack. No crack means the probability of crack is basically 0. Primary crack means the probability of crack is relatively high. Secondary crack means the probability of crack is high. Tertiary crack means the probability of crack is very high.

[0083] The crack type of the event is determined based on the fault type of the event.

[0084] If the fault type at that time is no fault, the crack type can be directly determined as no crack.

[0085] If the fault type at that time is a primary fault, the crack type can be directly determined as a primary crack.

[0086] If the fault type of the current time is any one of the secondary fault and the tertiary fault, further specific judgment is made according to the crack index of the current time. If any one of the first index and the second index is established, that is, R1 < R1a is established, or any one of R2 > R2a and R3 > R3a is established, the crack type is determined to be a secondary crack. If the first index and the second index are both established, that is, R1 < R1a and R2 > R2a are established, or R1 < R1a and R3 > R3a are established, the crack type is determined to be a tertiary crack.

[0087] Embodiment 2

[0088] An embodiment of a rotor radial crack fault identification system based on vibration signals, using the rotor radial crack fault identification method described in any one of the above, includes:

[0089] A vibration test module for performing a plurality of vibration tests on the rotor, and the plurality of vibration tests include historical vibration tests and current vibration tests. The historical vibration test is the first Nc tests.

[0090] A spectrum analysis module connected to the vibration test module for obtaining the vibration signals obtained from the vibration tests and performing spectrum analysis on the vibration signals.

[0091] A data processing module connected to the spectrum analysis module, obtaining the spectrum analysis result, obtaining a measured value, obtaining a calculated value according to the measured value, and obtaining a reference value according to the calculated value of the historical vibration test.

[0092] A fault judgment module connected to the data processing module, obtaining the current fault index and crack index according to the calculated value and the reference value of the current vibration test, and judging the current fault type according to the current fault index, and judging the current crack type according to the current fault type and the current crack index.

[0093] Specifically, the vibration test module uses an existing vibration test device to test the rotor to obtain vibration signals.

[0094] The spectrum analysis module uses an existing spectrum analysis device and spectrum analysis technology to analyze the vibration signals of the rotor, obtains the spectrum analysis result, and outputs the spectrum analysis result to the subsequent data processing module.

[0095] The data processing module can be a computer for processing the spectrum analysis result and judging the fault type and crack type according to various data.

[0096] When obtaining the reference value, the vibration testing module performs at least Nc tests on the rotor, and the spectrum analysis module performs spectrum analysis according to the vibration signal of each test, and outputs the spectrum analysis results, that is, the critical speed F1 of the first-order vibration, the critical speed F2 of the second-order vibration, the 1st-order vibration amplitude U1, the 2nd-order vibration amplitude U2, and the 3rd-order vibration amplitude U3 of the measured values ​​obtained in each test in the Nc tests.

[0097] The data processing module obtains the calculated values ​​Rc, R1, R2, and R3 corresponding to each test based on the measured values ​​of the critical speed F1 of the first-order vibration, the critical speed F2 of the second-order vibration, the 1st-time vibration amplitude U1, the 2nd-time vibration amplitude U2, and the 3rd-time vibration amplitude U3 obtained in each test in Nc tests, and further obtains the reference values ​​Rca, R1a, R2a, and R3a.

[0098] When the rotor is subjected to a crack test, the vibration test module performs a vibration test on the rotor, and the spectrum analysis module performs spectrum analysis on the vibration signal of the test and outputs the spectrum analysis result of the test, i.e., the critical speed F1 of the first-order vibration, the critical speed F2 of the second-order vibration, the 1st-order vibration amplitude U1, the 2nd-order vibration amplitude U2, and the 3rd-order vibration amplitude U3 of the measured values ​​of the test.

[0099] The data processing module obtains the calculated values ​​Rc, R1, R2, and R3 of the test based on the measured values ​​of the critical speed F1 of the first-order vibration, the critical speed F2 of the second-order vibration, the 1st-order vibration amplitude U1, the 2nd-order vibration amplitude U2, and the 3rd-order vibration amplitude U3 obtained in the test.

[0100] When analyzing the crack test results, the data processing module obtains the current fault index Kc and the current crack index based on the calculated values ​​Rc, R1, R2, R3 of the current test and the reference values ​​Rca, R1a, R2a, R3a obtained from the previous Nc tests. The data processing module further determines the current fault type based on the current fault index Kc, and then determines the current crack type based on the current fault type and the current crack index.

[0101] Preferably, the data processing module sets the fault type identifier as ID, where ID=0 indicates no fault, ID=1 indicates a primary fault, ID=2 indicates a secondary fault, and ID=3 indicates a tertiary fault. The initial value of ID is 0.

[0102] The data processing module sets the identification of the crack type as JD, JD=0 indicates no crack, JD=1 indicates primary crack, JD=2 indicates secondary crack, JD=3 indicates tertiary crack. The initial value of JD is 0.

[0103] When the data processing module finishes judging, it outputs the values ​​of ID and JD, and the crack information of the rotor can be obtained.

[0104] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0105] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0106] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0107] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0108] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A rotor radial crack fault identification method based on vibration signals, comprising: S1: Conduct at least Nc vibration tests on the rotor, obtain the vibration signals each time, perform spectral analysis on each vibration signal, obtain the measured values F1, F2, U1, U2, U3 based on the spectral analysis results each time, and then obtain the calculated values Rc, R1, R2, R3, and obtain the reference values Rca, R1a, R2a, R3a based on the calculated values Rc, R1, R2, R3 of the previous Nc times; Among them, Rc is the ratio of the critical speed F1 of the first-order vibration to the critical speed F2 of the second-order vibration, R1 is the change rate of the first-order critical speed, R2 is the ratio of the vibration amplitude U1 of the 1x frequency to the vibration amplitude U2 of the 2x frequency, R3 is the ratio of the vibration amplitude U1 of the 1x frequency to the vibration amplitude U3 of the 3x frequency, Rca is the average value of Rc in the previous Nc tests, R1a is the average value of R1 in the previous Nc tests, R2a is the average value of R2 in the previous Nc tests, and R3a is the average value of R3 in the previous Nc tests; S2: Conduct the (Nc + M)th vibration test on the rotor, obtain the current vibration signal, perform spectral analysis on the current vibration signal, and obtain the current Rc, R1, R2, R3 based on the current spectral analysis result; S3: Obtain the current fault index Kc according to the reference value Rca and the current Rc, Kc = |Rc - Rca| / Rc; Obtain the current crack index according to the reference values R1a, R2a, R3a and the current R1, R2, R3. The crack index includes a first index and a second index. The first index is R1 < R1a, and the second index is R2 > R2a or R3 > R3a; S4: Judge the current fault type according to the current fault index Kc, and judge the current crack type according to the current fault type and the current crack index.

2. The rotor radial crack fault identification method based on vibration signal according to claim 1 is characterized in that: Judging the current fault type according to the current fault index Kc includes: If the fault type has not been obtained before the current test, compare the current fault index Kc with e1. If Kc < e1, judge that the current fault type is no fault; among them, the value range of e1 is 0.02 - 0.08; If the fault type has been obtained before the current test, judge the current fault type according to the fault type before the current test and the current fault index Kc.

3. The rotor radial crack fault identification method based on vibration signals according to claim 2 is characterized in that: Judging the current fault type according to the fault type before the current test and the current fault index Kc includes: If the result of no fault has been obtained in the vibration test before the current test and the current fault index Kc > e1, compare the current Rc with e2. If |Rc - 1| < e2, judge that the current fault type is a first-level fault; among them, the value range of e2 is 0.02 - 0.05; If the result of a first-level fault has been obtained in the vibration test before the current test, compare the current fault index Kc with e3, e4. If |Rc - 1| > e3 and |Rc - 1| < e4, judge that the current fault type is a second-level fault, where the value range of e3 is 0.06 - 0.10, and the value range of e4 is 0.15 - 0.20; If the result of the fault type being a level 2 fault has been obtained in the vibration test before the current test, the current Rc is compared with e4. If |Rc-1|>e4, the current fault type is determined to be a level 3 fault.

4. The rotor radial crack fault identification method based on vibration signal according to claim 3 is characterized in that: Judging the current crack type based on the current fault type and the current crack index includes: If the current fault type is no fault, the crack type is judged to be no crack; If the current fault type is a primary fault, the crack type is determined to be a primary crack; If the current fault type is a level 2 fault or a level 3 fault, and any one of the first indicator and the second indicator is met, the crack type is determined to be a level 2 crack; If the current fault type is a level 2 fault or a level 3 fault, and the first indicator and the second indicator are both met, then the crack type is determined to be a level 3 crack.

5. The rotor radial crack fault identification method based on vibration signals according to claim 1 is characterized in that: Rc=F2 / F1.

6. The rotor radial crack fault identification method based on vibration signals according to claim 1 is characterized in that: R1=F1 / Fa, where Fa is the average value of the critical speed F1 of the first-order vibration.

7. The rotor radial crack fault identification method based on vibration signals according to claim 1 is characterized in that: R2=U2 / U1.

8. The rotor radial crack fault identification method based on vibration signals according to claim 1 is characterized in that: R3=U3 / U1.

9. The rotor radial crack fault identification method based on vibration signals according to claim 1, characterized in that: include: Nc is not less than 10.

10. A rotor radial crack fault identification system based on vibration signals, characterized in that: The rotor radial crack fault identification method based on vibration signals according to any one of claims 1 to 9 comprises: A vibration test module, used for performing several vibration tests on the rotor, wherein the several vibration tests include historical vibration tests and current vibration tests; A spectrum analysis module is connected to the vibration test module and is used to obtain a vibration signal obtained by the vibration test and perform spectrum analysis on the vibration signal; A data processing module is connected to the spectrum analysis module to obtain spectrum analysis results, obtain measurement values, obtain calculation values ​​based on the measurement values, and obtain reference values ​​based on the calculation values ​​of historical vibration tests; The fault judgment module is connected to the data processing module, obtains the current fault index and crack index according to the calculated value and reference value of the current vibration test, judges the current fault type according to the current fault index, and judges the current crack type according to the current fault type and the current crack index.

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