阅读说明：本技术 一种机翼单点失效结构健康监测方法 (Health monitoring method for single-point failure structure of wing ) 是由 刘腾达 高冠 刘泽峰 曾鹏 卫子雄 于 2021-09-15 设计创作，主要内容包括：本发明涉及一种撑杆式机翼单点失效结构健康监测方法,包括如下步骤：步骤一,测量单元使用传感器在撑杆顶面和侧面设置多个测点获取振动信号；步骤二,将振动信号发送至信号分析和处理单元,通过包络谱图分析方法进行信号的频域分析；步骤三,专家系统通过时域和频域的信号分析结果,判断出问题的根源；步骤四,向中央控制室发送监测报告,预警系统故障类型和故障等级。本发明通过振动传感器实时监测机翼撑杆,与完好撑杆、撑杆接头的振动频谱进行比较,当发现异常时及时报警,立即对结构进行检测,以达到保证撑杆结构可靠性、保障飞行安全的目的。(The invention relates to a health monitoring method for a single-point failure structure of a strut-type wing, which comprises the following steps: firstly, a measuring unit uses a sensor to set a plurality of measuring points on the top surface and the side surface of a stay bar to obtain vibration signals; secondly, sending the vibration signal to a signal analysis and processing unit, and carrying out frequency domain analysis on the signal by an envelope spectrogram analysis method; thirdly, the expert system judges the root of the problem according to the signal analysis results of the time domain and the frequency domain; and step four, sending a monitoring report to the central control room, and early warning the system fault type and the fault level. The invention monitors the wing stay bar in real time through the vibration sensor, compares the wing stay bar with the vibration frequency spectrum of the intact stay bar and the stay bar joint, alarms in time when abnormality is found, and immediately detects the structure, thereby achieving the purposes of ensuring the reliability of the stay bar structure and ensuring the flight safety.)

1. A health monitoring method for a single-point failure structure of a strut-type wing is characterized by comprising the following steps: firstly, a measuring unit uses a sensor to set a plurality of measuring points on the top surface and the side surface of a stay bar to obtain vibration signals; secondly, sending the vibration signal to a signal analysis and processing unit, and carrying out frequency domain analysis on the signal by an envelope spectrogram analysis method; thirdly, the expert system judges the root of the problem according to the signal analysis results of the time domain and the frequency domain; and step four, sending a monitoring report to the central control room, and early warning the system fault type and the fault level.

2. The method of claim 1, wherein the vibration signal in the first step comprises acceleration measurements, velocity measurements, and displacement measurements.

3. The method according to claim 1, wherein the method of analyzing the envelope spectrogram in the second step specifically comprises: firstly, preprocessing a signal; then, carrying out band-pass filtering on the signal to obtain a narrow-band signal; then carrying out Hilbert transform on the narrow-band signal to form an analytic signal; and extracting an amplitude envelope function of the analytic signal, and solving a frequency spectrum of the amplitude envelope function so as to obtain information reflecting the fault sideband component.

4. The method of claim 3, wherein the preprocessing is time domain averaging to reduce random noise and/or eliminate trend terms in the signal.

5. The method according to claim 3, wherein the information of the fault sideband component comprises a high frequency acceleration envelope effective value, which is the energy of the high frequency acceleration envelope after filtering low frequency components, and can reflect the impact energy generated during mechanical damage.

6. The method of claim 1, wherein the number of stations in step one is ten or more.

7. The method of claim 1, wherein the source of the problem is determined in step three by comparing the measured vibration signal with stored time domain waveforms and frequency domain eigenvalues of the three fault types.

8. The method of claim 7, wherein the stored time domain waveform and frequency domain characteristic values of the three fault types are obtained, and at least two key measuring points in different directions are selected when each fault type is subjected to frequency domain analysis.

9. The method of claim 1, wherein in the fourth step, the failure types comprise a strut crack or fissure, a hinge dislocation or inclusion of foreign matter, and an excessive strut chipping.

10. The method of claim 1, wherein in step four, the fault levels include two, a yellow alarm is unsuitable for long-term continuous operation, and a red alarm is required to service equipment to prevent potential faults.

Technical Field

The invention relates to a health monitoring method for a single-point failure structure of a wing, in particular to a real-time monitoring and early warning method for a strut-type wing.

Background

The existing strut type wing is not provided with a structural health monitoring device aiming at the strut and the strut joint, the state of the strut cannot be monitored in real time, and safety can only be ensured through periodic detection. The vibration is a phenomenon that the strut type wing inevitably generates in the working process, the vibration information contains rich information of the running state, and the change of the working performance of the strut type wing can be expressed through the vibration. If the stay bar is broken, the single-side wing can be failed instantly due to the hinged wing root, and further disastrous accidents can be caused. The invention solves the problem and monitors the health state of the stay bar and the stay bar joint in real time. And researching the vibration expression correlation of the typical fault at different measuring points and in different directions, ascertaining the characteristic relations of the typical fault such as the vibration position, the vibration signal and the like, and establishing a mapping relation between the vibration signal and the typical fault.

Disclosure of Invention

The invention relates to a health monitoring method for a single-point failure structure of a strut-type wing, which comprises the following steps: firstly, a measuring unit uses a sensor to set a plurality of measuring points on the top surface and the side surface of a stay bar to obtain vibration signals; secondly, sending the vibration signal to a signal analysis and processing unit, and carrying out frequency domain analysis on the signal by an envelope spectrogram analysis method; thirdly, the expert system judges the root of the problem according to the signal analysis results of the time domain and the frequency domain; and step four, sending a monitoring report to the central control room, and early warning the system fault type and the fault level.

Preferably, the vibration signal in the first step includes acceleration measurement, velocity measurement and displacement measurement.

Preferably, the method for analyzing an envelope spectrogram in the second step specifically includes: firstly, preprocessing a signal; then, carrying out band-pass filtering on the signal to obtain a narrow-band signal; then carrying out Hilbert transform on the narrow-band signal to form an analytic signal; and extracting an amplitude envelope function of the analytic signal, and solving a frequency spectrum of the amplitude envelope function so as to obtain information reflecting the fault sideband component.

Preferably, the preprocessing is to perform time domain averaging to reduce random noise and/or eliminate trend terms in the signal.

Preferably, the information of the fault sideband component includes a high-frequency acceleration envelope effective value, which is the energy of the high-frequency acceleration envelope after the low-frequency component is filtered out, and can reflect the impact energy generated during the mechanical damage.

Preferably, the number of the measuring points in the step one is more than ten.

Preferably, the method for determining the root cause of the problem in step three is to compare the measured vibration signal with the stored time domain waveform and frequency domain characteristic values of the three fault types.

Preferably, when the time domain waveform and the frequency domain characteristic value of the stored three fault types are obtained, two key measuring points are selected when each fault type is subjected to frequency domain analysis.

Preferably, the failure types include strut cracks or fractures, hinge misalignment or inclusion of foreign objects, and strut over-chipping.

Preferably, in the fourth step, the fault grades include two types, a yellow alarm is not suitable for long-term continuous operation, and a red alarm is required for repairing equipment to prevent potential faults.

The invention monitors the wing stay bar in real time through the vibration sensor, compares the wing stay bar with the vibration frequency spectrum of the intact stay bar and the stay bar joint, alarms in time when abnormality is found, and immediately detects the structure, thereby achieving the purposes of ensuring the reliability of the stay bar structure and ensuring the flight safety.

The method utilizes the characteristic that the vibration signal of the structural member can be influenced by the defects on the structural member, and realizes the judgment of the health condition of the structural member by monitoring the vibration signals of the stay bar and the stay bar joint in real time, thereby reducing the probability of catastrophic accidents caused by the failure of the wing to the maximum extent.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1(a) is a waveform of a vibration signal at a portion of test points for a failure type one of a strut crack or fracture;

FIG. 1(b) is a waveform of a vibration signal at a portion of test points for a failure type one of a strut crack or fracture;

FIG. 2 is a waveform diagram of a vibration signal for a fault type two of hinge misalignment or foreign object inclusion;

FIG. 3 is a waveform of a vibration signal for strut over-chipping fault type three;

fig. 4 is a block flow diagram of a monitoring method.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," and the like in the description and claims of the present invention and in the above-described drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

The fault characteristics are important basis for diagnosing the faults of the parts. The vibration signals of the fault strut type wing and the normal strut type wing are contrastively analyzed, the characteristic relation between the vibration signals transmitted to the top surface and the side surface of the strut and typical faults is researched and proposed, and the vibration performance correlation degree and the measurement position of each fault in different measurement points and different directions are analyzed and obtained. Typical faults include: the hinge comprises a stay bar, a hinge, a lubricating oil and a connecting rod, wherein the stay bar is provided with a crack or a crack (hidden defects generated during processing and preparation or excessive mechanical stress), a hinge is dislocated or foreign matters are mixed, and the stay bar is excessively worn (rusted due to compressive stress or water in the lubricating oil and other chemical substances). And vibration signals are collected and monitored by using a vibration sensor, and measuring points are distributed on the top surface and the side surface of the stay bar. The vibration signal data acquisition is carried out for three typical faults respectively, and the measurement data are shown in figures 1-3.

16 measuring points are arranged aiming at the fault type of the strut crack or fracture, wherein 8 measuring points are arranged on the top surface, 8 measuring points are arranged on the side surface, and the relation curve of the amplitude of the vibration signal and the time is shown in figure 1. The data analysis shows that the fundamental frequency of the vibration signal of the normal strut-type wing top surface measuring point compared with the side surface measuring point is very obvious, and is about 49Hz approximately, and the fundamental frequency is the main frequency component of the vibration signal. The vibration signal of the side measuring point has more high-frequency components, and the fundamental frequency is covered. The amplitude of the time domain vibration signal of the normal strut-type wing is small, the amplitude of the vibration of the fault strut-type wing is large, the larger the amplitude is, the more violent the vibration is, the richer the contained fault characteristic information is, the maximum amplitude is about 500 times of that of the normal strut-type wing, and the time domain vibration signal is triangular, as shown in fig. 1(a) and fig. 1 (b). In addition, vibration signals of different measuring points are different but have the same general trend, so that the measuring points with the representativeness can be selected for further analyzing the fault characteristics. The measuring points selected are considered to be distributed on the top surface and the side surface of the stay bar because the vibration directions of the two surfaces are different. The top surface vibration signal is in the Z direction, and the side surface vibration signal is in the X direction. The top surface can select the number 5 measuring points with larger signal amplitude, and the side surface can select the number 11 measuring points with the largest amplitude. And performing Fourier transform on the two points, and transforming the time domain signal into a frequency domain to analyze fault characteristic information.

The hinge can realize the connection between wing and the fuselage, and the hinge dislocation or mix with the foreign matter makes power and the vibration signal that the vaulting pole bore change. 17 measuring points are arranged aiming at the fault type of dislocation of the hinge or inclusion of foreign matters, wherein 9 measuring points are arranged on the top surface, 8 measuring points are arranged on the side surface, and the relation curve of the amplitude of the vibration signal and the time is shown in figure 2. The data analysis shows that one of the obvious characteristics of the fault strut type wing is that the vibration amplitude is increased and is about 30 times of the maximum normal value. Second, the top surface is larger in amplitude near point number 3 and the side surface is larger in amplitude near point number 15 because these two points are closer to the faulty hinge. The other measuring point which is worth paying attention is the measuring point No. 12, and the vibration impact signal direction of the measuring point No. 12 is opposite to that of the other measuring points, and the amplitude is larger. On the other hand, the number 12 measuring points have more wavelets, and the frequency band is a fault frequency and needs to be transformed into a frequency domain for specific analysis. The measuring points No. 12 and No. 15 contain fault characteristic information, but the measuring point No. 12 has more analysis value because the vibration signal has obvious fault frequency. Considering adding the measuring point No. 3 of another vibration direction, the two points are transformed to the frequency domain for further analysis.

The strut is excessively worn to cause the deterioration of supporting force and strength, 17 measuring points are arranged aiming at the type of the strut over-worn fault, wherein 9 measuring points are arranged on the top surface, 8 measuring points are arranged on the side surface, and the relation curve of the amplitude of the vibration signal and the time is shown in figure 3. The time domain vibration signal analysis shows that compared with a normal vibration signal, the amplitude of the fault vibration signal is reduced at the measuring points 1, 2, 3, 5, 6, 9 and 11 by about 2 times, compared with the normal vibration signal, the fundamental frequency waveform of the measuring point of the No. 2 vibration signal is completely covered, and the measuring point of the No. 2 vibration signal can be used as a fault monitoring point on the top surface. The normal No. 15 measuring point is filled with the signal vibration amplitude at the wave trough, and the fault strut type wing No. 15 measuring point is filled with the signal vibration amplitude at the wave crest, and the vibration amplitude is increased. The measuring points can be used as fault monitoring points on the side surface, and the two measuring points are converted into a frequency domain for analysis.

The method for transforming the time domain waveform signal into the frequency spectrum signal for analysis is frequency spectrum analysis, and the frequency domain adopts an envelope spectrogram analysis method. The signal is first preprocessed, for example, time domain averaging to reduce random noise, remove trend terms in the signal, etc. And then, carrying out band-pass filtering on the signal to obtain a narrow-band signal. Then, the narrow-band signal is subjected to Hilbert transform to form an analysis signal. And extracting an amplitude envelope function of the analytic signal, and solving a frequency spectrum of the amplitude envelope function so as to obtain information reflecting a fault sideband component, particularly a high-frequency acceleration envelope effective value which is energy of the high-frequency acceleration envelope after low-frequency components are filtered and mainly reflects impact energy generated during mechanical damage.

By the method for acquiring and analyzing the data, a roughly interval range which can be operated, is not suitable for long-term operation and is damaged is provided for vibration monitoring. The possibility of potential failure of the equipment in the future can be predicted by vibration monitoring. The method provides guidance for online monitoring of the equipment and provides different levels of alarms, for example, green is in a normal state, yellow alarm is not suitable for long-term continuous operation, and red alarm means that the equipment needs to be overhauled to prevent potential faults.

The system monitoring flow chart is shown in fig. 4. Firstly, a measuring unit measures vibration signals of a mechanical system such as acceleration, speed and displacement by using a sensor, the vibration signals enter a signal analyzing and processing unit, frequency domain analysis is carried out on the signals by an envelope spectrogram analysis method and the signals are sent to an expert system, the expert system judges the root cause of a problem according to the signal analysis results of a time domain and a frequency domain, and then the system sends a monitoring report to a central control room to early warn the fault type and the fault level of the system.

The invention monitors the wing stay bar in real time through the vibration sensor, compares the wing stay bar with the vibration frequency spectrum of the intact stay bar and the stay bar joint, alarms in time when abnormality is found, and immediately detects the structure, thereby achieving the purposes of ensuring the reliability of the stay bar structure and ensuring the flight safety.

The method utilizes the characteristic that the vibration signal of the structural member can be influenced by the defects on the structural member, and realizes the judgment of the health condition of the structural member by monitoring the vibration signals of the stay bar and the stay bar joint in real time, thereby reducing the probability of catastrophic accidents caused by the failure of the wing to the maximum extent.

The above embodiments of the present invention are described in detail, and the principle and the implementation of the present invention are explained by applying specific embodiments, and the above description of the embodiments is only used to help understanding the method of the present invention and the core idea thereof; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.