CN-116359082-B - Three-dimensional detection system of lubricating oil abrasive particles based on phase shift micro mirror

CN116359082BCN 116359082 BCN116359082 BCN 116359082BCN-116359082-B

Abstract

The invention provides a three-dimensional detection system for lubricating oil abrasive particles based on a phase shift micro mirror, which comprises a light source system, a beam splitter, an abrasive particle imaging system, a phase modulation system and a detection system, wherein the light source system is used for emitting a beam of parallel light beams to be incident to the beam splitter, the beam splitter divides the parallel light beams into two identical transmission light beams and reflection light beams, the reflection light beams are incident to an oil abrasive particle detection area through the abrasive particle imaging system to generate a scattering light beam primary path to be returned to the beam splitter, the transmission light beams are modulated by the phase modulation system to form a reference light beam primary path to be returned to the beam splitter, the reference light beam and the scattering light beam interfere at the emergent position of the beam splitter to form interference light beams and then are incident to the detection system to obtain interference spectrum information, the amplitude and phase information of cross-correlation items in an interference light intensity expression are extracted from the interference spectrum information to construct a complex function of interference light beam signals, and then Fourier transformation is carried out on the complex function to finally obtain a clear three-dimensional reconstruction image of the lubricating oil abrasive particles.

Inventors

ZHENG KAIFENG
LIANG JINGQIU
LV JINGUANG
ZHAO BAIXUAN
QIN YUXIN
ZHAO YINGZE
CHEN YUPENG
WANG WEIBIAO

Assignees

中国科学院长春光学精密机械与物理研究所

Dates

Publication Date: 20260505
Application Date: 20230310

Claims (9)

1. The system is characterized by comprising a light source system, a beam splitter, an abrasive particle imaging system, a phase modulation system and a detection system; The light source system is used for emitting a parallel light beam to be incident to the beam splitter; the beam splitter divides the parallel light beam into two identical transmission light beams and reflection light beams which are respectively incident to the phase modulation system and the abrasive particle imaging system; the abrasive particle imaging system is used for imaging the lubricating oil samples at different positions on the oil abrasive particle detection area, and the oil abrasive particle detection area is used for bearing the lubricating oil samples extracted from the aeroengine; the abrasive grain imaging system comprises a scanning reflector and an objective lens; The reflected light beams are reflected by the scanning reflector and converged by the objective lens and then are incident into the oil abrasive particle detection area, the oil abrasive particle detection area is illuminated, and after interaction with abrasive particles in the lubricating oil sample, a scattered light beam primary path with the lubricating oil sample information is generated and returned to the beam splitter; Imaging the lubricating oil sample at different positions through the rotary motion of the scanning reflector and the translational motion of the oil abrasive particle detection area; The transmission light beam passes through different optical paths under the modulation action of the phase modulation system and returns to the beam splitter as a reference light beam original path, the phase modulation system comprises a phase shift micro mirror, each phase shift micro mirror consists of steps, each step corresponds to one phase modulation channel, the light beam in each phase modulation channel passes through different optical paths under the modulation action of the phase shift micro mirror, and when the number of the steps of the phase shift micro mirror is n, the space arrangement of the steps can enable each phase modulation channel to generate The interference spectrum signals of n channels of the to-be-measured point are obtained through one-time imaging: The reference beam and the scattered beam interfere at the emergent position of the beam splitter to form an interference beam, and the interference beam is incident to a detection system to obtain interference spectrum information of the interference beam; And extracting amplitude and phase information of a cross correlation term in the interference light intensity expression from the interference spectrum information to construct a complex function of an interference light beam signal, and carrying out Fourier transform on the complex function to finally obtain a clear three-dimensional reconstruction image of the lubricating oil abrasive particles.
2. The phase-shift micro-mirror based lubricating oil abrasive particle three-dimensional detection system according to claim 1, wherein the light source system comprises a light source and a collimating mirror; The light source is a near infrared broadband light source, low-coherence light emitted by the light source is incident to the collimating mirror, and is collimated by the collimating mirror to become parallel light beams to be incident to the beam splitter.
3. The three-dimensional inspection system of phase shift micromirror-based oil abrasive particles according to claim 2, wherein the beam splitter is placed at 45 ° angle to the optical axis with a split ratio of 1:1.
4. The three-dimensional inspection system for lubricating oil abrasive particles based on phase-shifting micro-mirrors according to claim 3, wherein the phase-shifting micro-mirrors can be manufactured by MOEMS technology, and each step surface is plated with a reflective film.
5. The three-dimensional detection system for the lubricating oil abrasive particles based on the phase-shift micro mirror according to claim 4, wherein the detection system comprises a dispersion grating, a cylindrical mirror and an area array detector; The interference light beam is dispersed by the dispersion grating, and is converged to the area array detector after being refracted by the cylindrical mirror to obtain interference spectrum information of the interference light beams of different phase modulation channels.
6. The three-dimensional inspection system for oil particles based on phase shift micromirrors according to claim 5, characterized in that the oil sample is scanned by a rotational movement of a scanning mirror, which is rectangular and rotates with its symmetry axis as a rotational center, which coincides with the image-side focus of the objective lens.
7. The three-dimensional detection system for oil abrasive particles based on phase-shift micromirrors according to claim 6, wherein the translational movement of the oil abrasive particle detection area is realized by a high-precision stepper motor, and the scanning direction of the scanning mirror is perpendicular to the moving direction of the oil abrasive particle detection area.
8. The phase-shift-micromirror-based three-dimensional inspection system for oil abrasive grains according to claim 7, wherein for a static phase-modulated light beam in any of the phase modulation channels: Let the reference beam signal be: Wherein, the As a function of the spectral power distribution of the reference beam, In order to be a phase of the light, For the optical path length of the reference beam, Wave number; let the scattered beam signal be: Wherein, the As a function of spectral power density of reflected light from different depth layers of the lubricating oil sample, For the refractive index of the lubricating oil sample, For a depth of the lubricating oil sample of Is a light path of the reflected light; An interference spectrum signal generated after the interference of the reference beam and the scattered beam The method comprises the following steps: the actual detection of the area array detector is an interference spectrum signal Is the real part of (2) Then actually interfere with the spectrum signal The expression of (2) is: For actual interference spectrum signals The intermediate item in the channel is subjected to Fourier transformation to obtain the depth information of the lubricating oil sample under the channel The method comprises the following steps: The depth information acquisition of the single-channel lubricating oil sample has direct-current item interference and cross-correlation item interference of reflection of each depth layer, and in addition, as the area array detector can only acquire real part information of interference spectrum signals, imaginary part information can not be acquired, and conjugate mirror image interference is caused; Then the wavelength is Is a function of the interference signal of (a) The simplification is as follows: Wherein, the The direct current term and the self-coherent term; And phi is the amplitude and phase of the interference signal, respectively; The wavelength obtained on the area array detector is Real part of interference signal of (2) : 。
9. The phase shift micromirror-based three-dimensional inspection system for lubricating oil abrasive particles according to claim 8, wherein the amplitude of the interference signal is solved And phase of And constructing a complex function of the interference signal, and carrying out Fourier transformation on the complex function of the interference signal to obtain the depth information of the lubricating oil abrasive particles.

Description

Three-dimensional detection system of lubricating oil abrasive particles based on phase shift micro mirror Technical Field The invention relates to the technical field of imaging instruments, in particular to a three-dimensional detection system for lubricating oil abrasive particles based on a phase shift micro mirror. Background The aeroengine is a key part of an aircraft, has a complex internal structure, is easy to generate the problem of part abrasion under the conditions of high temperature and high load, and seriously threatens the operation safety of the aeroengine. In major accidents of aircraft due to mechanical causes, about 40% are caused by engine failure, with wear-induced failures accounting for over 80%. Therefore, the abrasion state of the aero-engine is detected, and the method has great significance in accelerating the development of the aero-engine, guaranteeing the service safety and avoiding catastrophic safety accidents. The lubricating oil is used for lubricating, cooling and cleaning movable parts such as bearings, gears and the like of an aeroengine, and when the engine is worn, abrasive particles generated on the surfaces of the parts can enter a lubricating oil system, so that the oil contains abrasive particles with different shapes generated by various types of wear. When the generation rate of abrasive particles suddenly increases, abnormal abrasion of the engine is indicated, the abrasion position of the engine can be judged according to the form and the components of the abrasive particles, and the abrasion type and the abrasion degree can be judged according to the number, the shape and the size of the abrasive particles. Therefore, the abrasion state of the aeroengine equipment can be effectively estimated by detecting the characteristic parameters such as the quantity, the size, the shape and the like of the abrasive particles in the lubricating oil. The existing abrasive particle detection method is to acquire various indexes of the lubricating oil abrasive particles by adopting optical, electromagnetic, chemical and other methods so as to judge the abrasion state of the aeroengine. The detection method can be divided into off-line detection and on-line detection, the off-line detection usually comprises the steps of collecting an oil sample, and then analyzing the oil sample by adopting a ferrograph method, a scanning electron microscope or an atomic emission spectrum method, and the like, so that the detection accuracy is high, but the detection method consumes large manpower and material resources, and the abrasion state information of the engine cannot be obtained in time. The existing online detection method mainly adopts a detector based on electromagnetic induction, is mostly limited to detection of the particle size and quantity of lubricating oil, and cannot acquire shape information. At present, the abrasive grain detection technology has higher detection sensitivity and higher counting reliability, and meanwhile, abrasive grain information is developed from simple original signal feature extraction to graphic image analysis and fine feature extraction classification. Disclosure of Invention In view of the above problems, the invention aims to provide a three-dimensional detection system for lubricating oil abrasive particles based on a phase shift micro mirror, which extracts three-dimensional information of abrasive particles based on an optical interference principle, solves the problem that the traditional detection method is difficult to realize three-dimensional imaging of abrasive particles, acquires interference spectrums of a sample beam and a reference beam by utilizing a Michelson interference structure, and performs Fourier transform and other treatments to realize three-dimensional imaging of abrasive particles. Meanwhile, the phase shift micro-mirror structure is adopted to realize multi-channel static phase modulation, so that the problems of mirror image and parasitic image of single-channel interference imaging are solved, and the phase shift micro-mirror structure has the advantages of high imaging speed, high definition, good stability and compact structure. In order to achieve the above purpose, the present invention adopts the following specific technical scheme: The invention provides a three-dimensional detection system for lubricating oil abrasive particles based on a phase shift micro mirror, which comprises a light source system, a beam splitter, an abrasive particle imaging system, a phase modulation system and a detection system, wherein the beam splitter is arranged on the light source system; The light source system is used for emitting a parallel light beam to be incident to the beam splitter; the beam splitter divides the parallel light beam into two identical transmission light beams and reflection light beams which are respectively incident to the phase modulation system and the abrasive particle imaging system; The abrasive pa