CN113984384A

CN113984384A - Armored vehicle gear box fault diagnosis method based on tandem type fiber bragg grating vibration sensitive element

Info

Publication number: CN113984384A
Application number: CN202111239279.5A
Authority: CN
Inventors: 魏鹏; 郑鹏飞; 吕建勋; 刘颖异; 袁海文; 李成贵
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-10-25
Filing date: 2021-10-25
Publication date: 2022-01-28

Abstract

The invention provides a fault diagnosis method for a gearbox of an armored vehicle based on series fiber bragg grating vibration sensitive elements, which mainly comprises two parts of sensing and demodulation. Wherein, the sensing part is realized by adopting a serial fiber bragg grating which is pasted inside the gearbox of the armored car; the demodulation part adopts a resonance demodulation technology and comprises signal processing steps of band-pass filtering, envelope demodulation, low-pass filtering, Fourier transform and the like. Compared with a method for measuring vibration signals by an electric sensor, the fiber bragg grating with small volume and light weight can realize the measurement of the vibration signals in a narrow space, and can perform action and static measurement in an environment with constant temperature and large temperature change; in addition, the optical sensor based on wavelength modulation has the advantages of high stability, electromagnetic interference resistance and the like of the fiber bragg grating, and the fault type of the gearbox of the armored vehicle can be accurately diagnosed by combining a resonance demodulation technology.

Description

Armored vehicle gear box fault diagnosis method based on tandem type fiber bragg grating vibration sensitive element

Technical Field

The invention belongs to the technical field of fiber grating sensing, and is mainly used for fault diagnosis of broken teeth, gear grinding, defects and the like of a gear box of an armored car.

Background

The fiber grating vibration sensing technology is a sensing technology which can detect the characteristic change of light by carrying out signal acquisition and analysis through special detection equipment when the fiber grating is influenced by external vibration and part of the characteristics of the light transmitted in the optical fiber are changed, thereby detecting the vibration condition of an object. With the continuous development of sensing technology, the technical requirements of people on the sensor are also increasing. It is rare that a vibration sensor having high sensitivity, low cost, simple preparation process and good stability can be simultaneously satisfied. In the sensing detection process, the sensitivity and the stability are main technical influence factors, and the preparation process and the cost are important influence factors in the industrial production process. Vibration sensors that combine these advantages are gaining increasing attention and interest.

The failure types of the gear box are various, and mainly comprise abrasion, cracks, pitting corrosion, deformation and the like of inner and outer rings of a bearing, broken teeth, tooth surface abrasion, tooth root cracks and the like of a gear and a gear ring. The gearbox generates a complex series of vibration signals during operation due to meshing between gear teeth and collisions between shafting. The existing gear box fault diagnosis generally adopts piezoelectric ceramic acceleration sensors, resistance strain gauges and other electric sensors to acquire vibration signals outside the gear box, but the electric sensors are high in cost and large in size, can only be placed outside the gear box, and cannot work in an environment with electromagnetic interference. The fiber grating vibration sensor is a novel sensor, optical signals are used as signal carriers, and optical fiber transmission lines are also used for signal transmission. The fiber grating vibration sensor can resist electromagnetic interference in the vibration testing process and can be normally used in a high-current and high-intensity magnetic field environment; electrical insulation, which is determined by the fiber material; the volume is small, the weight is light, the networking is easy, and the quasi-distributed vibration measurement remote sensing can be realized.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the existing technical difficulty, and adopts the series fiber bragg grating to collect the vibration signal of the gearbox of the armored car and processes the signal by a resonance demodulation method, thereby accurately diagnosing the fault type of the gearbox of the armored car. The method has the characteristics of high sensitivity, strong penetrating power, electromagnetic interference resistance, suitability for dynamic and static detection, suitability for working in constant temperature and variable temperature environments and the like.

The technical scheme adopted by the invention is as follows: a fault diagnosis method for a gearbox of an armored car based on tandem fiber bragg grating vibration sensitive elements is disclosed. The serial fiber bragg grating is adopted to collect vibration signals of the gearbox of the armored car, and data processing is carried out through a resonance demodulation method, so that the fault type of the gearbox of the armored car is judged. The tandem type fiber bragg grating refers to that one optical fiber is provided with a plurality of fiber bragg gratings with different central wavelengths. The method comprises the following specific contents:

and adhering the serial fiber bragg grating to a plurality of measured point positions in the gearbox of the armored car by using instant adhesive. The position of the measured point refers to a fixed non-rotating part or position in the gearbox of the armored vehicle. One end of the tandem type fiber bragg grating is connected with a fiber bragg grating demodulator through an optical fiber, and the fiber bragg grating demodulator is used for collecting central wavelength information of reflected light of the fiber bragg grating. When certain types of defects exist in the gearbox of the armored car, the vibration signal generated in the operation process of the gearbox of the armored car can contain periodic fault signals. The vibration signal changes the refractive index or grating period of the fiber grating in the form of a rapid strain, thereby changing its center wavelength.

Due to strong interference of noise, fault diagnosis is difficult to directly carry out in an original vibration signal, and a resonance demodulation technology is adopted to extract the fault signal. Firstly, performing band-pass filtering on a signal, then performing envelope demodulation on the signal to convert a high-frequency signal into a low-frequency signal, and then performing low-pass filtering and Fourier transform on the signal to obtain a frequency spectrum of the envelope low-frequency signal. Several types of faults of the gearbox of the armored vehicle have corresponding fault frequencies, and the fault frequencies can be calculated through parameters of the gearbox. By comparing the frequency spectrum and the amplitude thereof with the fault frequency table, the fault type of the gearbox of the armored vehicle can be diagnosed.

Compared with the prior art, the invention has the advantages that: the fiber grating vibration sensor has small volume and light weight, and can measure vibration signals in a narrow space; the tandem fiber grating vibration sensor can measure a plurality of positions simultaneously. Compared with an electric sensor, the fiber grating vibration sensor has low cost. Because the sensor is based on wavelength modulation, the fiber grating vibration sensor has high stability and accuracy, resists electromagnetic interference and can still normally work in an environment with large temperature change. The resonance demodulation technology is accurate and reliable in fault diagnosis. The fiber grating vibration sensor is matched with a resonance demodulation technology to diagnose the fault of the gearbox of the armored car, and an accurate result can be obtained.

Drawings

FIG. 1 is a method of diagnosing a fault in an armored car gearbox with a tandem fiber grating vibration sensor;

FIG. 2 is a schematic diagram of an embodiment of the present invention;

in the figure: the system comprises a power supply, a fault armored car gearbox 1, a serial fiber grating vibration sensor 2, a fiber grating demodulator 3, a band-pass filter 4, an envelope demodulator 5, a low-pass filter 6, a Fourier transform 7 and a fault diagnosis 8. Wherein 4, 5, 6 and 7 belong to the specific steps of the resonance demodulation technology 9. And 10 is an inner gear ring of the gearbox of the armored vehicle.

Detailed Description

The invention is further described with reference to the following figures and detailed description.

The ring gear 10 is a fixed non-rotating component in the armored car gearbox 1. The series fiber grating vibration sensor 2 which is not packaged is pasted on a plurality of positions of the inner gear ring 10 of the planetary gear case 1 by 502 instant adhesive, one end of the optical fiber is connected with the fiber grating demodulator 3, and the other end is freely placed. When the gear box rotates at a constant speed, the vibration signal containing the fault characteristic frequency of the inner gear ring 10 can change the central wavelength of the fiber bragg grating 2. The fiber grating demodulator 3 collects the central wavelength changes of all fiber gratings as original vibration signals. And then the resonance demodulation technology is utilized to process the signals, so that the frequency spectrum information of the vibration signals can be obtained. The fault characteristic frequency of the inner gear ring 10 can be calculated through parameters such as the rotating speed of the gear box 1, the number of planet wheels and the number of teeth. By comparing the frequency spectrum information of the vibration signal, the fault type of the ring gear 10 can be judged.

Although illustrative embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the embodiments, and various changes may be made apparent to those skilled in the art as long as they are within the spirit and scope of the present invention as defined and defined by the appended claims, and all matters of the invention which utilize the inventive concepts are protected.

Claims

1. A fault diagnosis method for an armored car gear box based on a tandem type fiber bragg grating vibration sensing element is characterized in that a tandem type fiber bragg grating (2) is pasted at a plurality of measured point positions (1) in the armored car gear box through instant adhesive. One end of the tandem type fiber grating (2) is connected with a fiber grating demodulator (3) through an optical fiber, and the fiber grating demodulator (3) is used for collecting the central wavelength information of the reflected light of the tandem type fiber grating (2). When the gearbox (1) of the armored vehicle has certain defects, periodic fault signals exist in vibration signals generated in the operation process of the gearbox (1) of the armored vehicle. The vibration signal changes the refractive index or grating period of the fiber grating (2) in the form of a rapid strain, thereby changing its center wavelength.

Due to strong interference of noise, fault diagnosis (8) is difficult to directly carry out on the original vibration signal, and the resonance demodulation technology (9) can be used for filtering the noise to realize the extraction of the fault signal. The method comprises the following specific steps: firstly, the signal is subjected to band-pass filtering (4) to filter partial noise, then envelope demodulation (5) is carried out to convert a high-frequency signal into a low-frequency signal, and then low-pass filtering (6) and Fourier transform (7) are carried out on the signal to obtain the frequency spectrum of the envelope low-frequency signal. Several types of faults of the gearbox (1) of the armored vehicle have corresponding fault frequencies, and the fault frequencies can be calculated through parameters of the gearbox (1) of the armored vehicle. By comparing the frequency spectrum and its amplitude with a fault frequency table, a fault diagnosis (8) of the armored car gearbox (1) can be performed.

2. The method for diagnosing the fault of the gearbox of the armored vehicle based on the tandem type fiber bragg grating vibration sensitive elements as claimed in claim 1, wherein the method comprises the following steps: the tandem type fiber bragg grating is formed by arranging a plurality of fiber bragg gratings with different central wavelengths on one optical fiber.

3. The method for diagnosing the fault of the gearbox of the armored vehicle based on the tandem type fiber bragg grating vibration sensitive elements as claimed in claim 1, wherein the method comprises the following steps: the position of the measured point is a part or a position which is fixed inside the gear box (1) of the armored vehicle and does not rotate along with any gear.