Bearing roller appearance line scanning stripe detection device based on polarization interference

Abstract

The utility model discloses a bearing roller appearance line scanning fringe detection device based on polarization interference. The bearing roller appearance line scanning fringe detection device comprises a transmitting end (20) and a receiving end (18), the transmitting end (20) comprises a linear polarization laser (1), and an orthogonal polarization beam generation module (17) and a linear diffusion plate (6) are sequentially arranged in the laser transmitting direction of the linear polarization laser (1); the receiving end (18) comprises an imaging lens (11), and the imaging lens (11) is sequentially provided with a second half-wave plate (12) and a spectroscope (13) along the laser transmission direction; according to the utility model, the cross-polarization laser is generated through the cross-polarization beam generation module, the polarization interference effect of the cross-polarization laser is imaged and obtained by the receiving end, the influence of environmental factors and high reflection on the projection process and the reflection image is reduced, and the obtained image information comprises a plurality of information sources. And the accuracy of identification and detection is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of appearance detection, in particular to a bearing roller appearance line scanning stripe detection device based on polarization interference. Background Art

[0002] The basis of laser interferometry is the typical interference optical path of the Michelson interferometer, which uses the interference optical path to allow the laser emitted by the laser source to be directed to the measuring surface and the reference surface respectively, and then reflected back by the measured surface and the reference surface. The reflected lasers will interfere after merging, and the absolute distance between the measuring surface and the reference surface is calculated by the interference light intensity. This is the principle of laser interferometry. The light and dark changes of the interference fringes reflect the phase difference between the object light and the reference light. These phase differences are related to the ups and downs of the surface of the object. The interference pattern is captured by an optical imaging system, and the image is processed and analyzed by a computer, so that the surface morphology of the object being measured can be accurately measured; for example, the Chinese invention patent with publication number CN112505057A discloses a rolling surface defect detection system and method, which adjusts the Gaussian laser beam to a flat-top beam, changes the driving signal of the galvanometer, and obtains three different target images of the flat-top beam irradiated on the rotating rolling surface to be measured after being scanned by the galvanometer. Based on the three different target images, a three-step phase shift calculation is performed. The method extracts the wrapped phase information of the rolling surface to be tested, and obtains the modulation map of the rolling surface to be tested through the wrapped phase information. The light intensity of the flat-top light beam changes with time, so different target images with a certain phase difference in the fringe can be obtained by changing the driving signal of the galvanometer. Based on the three different target images, the wrapped phase information of the rolling surface to be tested can be further extracted through the three-step phase shift algorithm. However, the light beam of this method is directly projected onto the surface of the object to be tested after shaping and galvanometer, which is easily affected by environmental factors such as vibration, humidity and temperature. At the same time, the recognition device directly obtains the surface image information of the object to be tested for calculation, which will be affected by high reflective factors and has the problem of insufficient detection accuracy. Utility Model Content

[0003] The purpose of the utility model is to provide a bearing roller appearance line scanning stripe detection device based on polarization interference. The utility model generates orthogonal polarized lasers through an orthogonal polarized beam generation module, and the polarization interference effect of the orthogonal polarized lasers is imaged and acquired by the receiving end, reducing the influence of environmental factors and high reflection on the projection process and reflected images. At the same time, the image information obtained contains multiple information sources, effectively improving the accuracy of recognition and detection.

[0004] The technical solution of the utility model is as follows: a bearing roller appearance line scanning fringe detection device based on polarization interference, comprising a transmitting end and a receiving end; the transmitting end comprises a linear polarization positive laser, and the laser emission direction of the linear polarization positive laser is provided with an orthogonal polarization beam generating module and a linear diffusion plate in sequence; the receiving end comprises an imaging lens, and the imaging lens is provided with a second half-wave plate and a beam splitter in sequence along the laser transmission direction, and a second polarization beam splitter and a third polarization beam splitter are provided in the transmission and reflection directions of the beam splitter respectively; and linear array cameras are provided in the polarization light path directions of the second polarization beam splitter and the third polarization beam splitter respectively.

[0005] In the above-mentioned bearing roller appearance line scan fringe detection device based on polarization interference, the orthogonal polarized light beam generating module includes a first polarization beam splitter for receiving laser light emitted by a linear polarization laser, and the first polarization beam splitter is provided with a first 1 / 4 wave plate and a first reflector in both the p-polarization light path direction and the s-polarization light path direction.

[0006] In the aforementioned bearing roller appearance line scanning fringe detection device based on polarization interference, a speckle attenuator is arranged in front of the linear polarization laser.

[0007] In the aforementioned bearing roller appearance line scanning fringe detection device based on polarization interference, a first half-wave plate is arranged in front of the speckle reducer.

[0008] In the aforementioned bearing roller appearance line scanning fringe detection device based on polarization interference, a beam expansion system is arranged in front of the first half-wave plate.

[0009] In the aforementioned bearing roller appearance line scanning fringe detection device based on polarization interference, the linear polarization laser is a single-mode laser.

[0010] In the aforementioned bearing roller appearance line scan fringe detection device based on polarization interference, a second reflector is provided between the orthogonal polarized light beam generating module and the linear diffuser, the incident direction of the second reflector is toward the first polarization beam splitter, and the reflection direction of the second reflector is toward the linear diffuser.

[0011] In the aforementioned bearing roller appearance line scan fringe detection device based on polarization interference, a second 1 / 4 wave plate is provided between the beam splitter and the third polarization beam splitter.

[0012] Compared with the prior art, the linear polarization laser at the transmitting end of the utility model emits linear polarized light, the linear polarized light enters the orthogonal polarization beam generating module, is divided into p-polarized light and s-polarized light by the first polarization beam splitter, the p-polarized light and the s-polarized light are respectively combined to form an orthogonal polarized laser after being acted upon by the corresponding first 1 / 4 wave plate and the first reflector, the orthogonal polarized laser is directed toward the bearing roller to be measured rotating on the object placing turntable, the orthogonal polarized laser reflected by the bearing roller to be measured enters the receiving end, is received by the imaging lens, and then successively passes through the second half-wave plate and the beam splitter to become reflected light and transmitted light, the transmitted light enters the second polarization beam splitter to become the first p-polarized light and the first s-polarized light, the first p-polarized light and the first s-polarized light respectively enter the corresponding linear array camera; the reflected light passes through the second 1 After the / 4 wave plate enters the third polarization beam splitter, it becomes the second p-polarized light and the second s-polarized light. The second p-polarized light and the second s-polarized light enter the corresponding linear array cameras respectively, and then the four groups of linear array cameras capture the π / 2 four-step phase-shifted fringe pattern; combining polarization interference and line scanning fringe imaging strategies, it effectively solves the problems of traditional surface structured light projection under defocus and high reflection conditions, and at the same time overcomes the shortcomings of traditional interference technology such as small detection range, sensitivity to background light and environmental vibration, and temperature and humidity changes, and realizes a wider range of application scenarios. At the same time, the obtained π / 2 four-step phase-shifted fringe pattern contains multiple information sources such as visual images generated by stripes, polarization information, stripe images and their derivative images, 3D information, etc. The accuracy of defect recognition can be effectively improved through multi-information fusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a structural diagram of the device of the present utility model.

[0014] The markings in the attached figure are: 1-linear polarization laser; 2-speckle attenuator; 3-first half-wave plate; 4-beam expansion system; 5-second reflector; 6-linear diffuser; 7-turntable; 8-first polarization beam splitter; 9-first 1 / 4 wave plate; 10-first reflector; 11-imaging lens; 12-second half-wave plate; 13-beam splitter; 14-second polarization beam splitter; 15-second 1 / 4 wave plate; 16-third polarization beam splitter; 17-orthogonal polarization beam generating mode; 18-receiving end; 19-linear array camera; 20-transmitting end. DETAILED DESCRIPTION

[0015] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0016] Embodiment: A device for detecting line scan stripes of the appearance of a bearing roller based on polarization interference, comprising a transmitting end 20 and a receiving end 18; the transmitting end 20 comprises a linear polarization laser 1, and the laser emission direction of the linear polarization laser 1 is sequentially installed with an orthogonal polarization beam generating module 17, a linear diffuser 6 and a storage turntable 7, the linear diffuser is used to change the shape of the beam, and can convert a point light source into a line light source, while reducing high reflection and preventing overexposure; the orthogonal polarization beam generating module 17 comprises a first polarization beam splitter 8 for receiving the laser emitted by the linear polarization laser 1, and the first polarization beam splitter 8 is installed with a first 1 / 4 wave plate in both the p-polarization light path direction and the s-polarization light path direction 9 and a first reflector 10, the reflection directions of the two first reflectors 10 are both toward the first polarization beam splitter 8, and the first reflector can be fine-tuned to correct the light beam; the receiving end 18 includes an imaging lens 11 facing the object turntable 7, and the imaging lens 11 is sequentially installed with a second half-wave plate 12 and a beam splitter 13 along the laser transmission direction, and a second polarization beam splitter 14 and a third polarization beam splitter 16 are respectively installed in the transmission and reflection directions of the beam splitter 13, and a second 1 / 4 wave plate 15 is arranged between the beam splitter 13 and the third polarization beam splitter 16; the p-polarization light path direction and the s-polarization light path direction of the second polarization beam splitter 14 and the p-polarization light path direction of the third polarization beam splitter 16 Linear array cameras 19 are installed in the a- and s-polarization light paths respectively; the first quarter wave plate 9 and the second quarter wave plate 15 are used to adjust the polarization state of the light wave so that the polarization direction of the light wave rotates 45 degrees; the first polarization beam splitter, the second polarization beam splitter and the third polarization beam splitter are used to separate or merge light beams with different polarization directions; a speckle attenuator 2, a first half-wave plate 3 and a beam expansion system 4 are also installed in sequence between the linear polarization laser 1 and the orthogonal polarization beam generating module 17 along the laser emission direction; the speckle attenuator is a device for reducing speckle noise in the laser beam, and improves the imaging quality by making the light spot uniform; the first half-wave plate and the second half-wave plate Used to adjust the polarization state of light and change the polarization direction of light passing through it; the beam expansion system is used to proportionally amplify linearly polarized light; the linear polarization laser 1 is a single-mode laser, a laser that only produces one mode of light beam, usually outputting light of a single color; a second reflector 5 is installed between the orthogonal polarized light beam generating module 17 and the linear diffuser 6, the incident direction of the second reflector 5 is toward the first polarization beam splitter 8, and the reflection direction of the second reflector 5 is toward the linear diffuser 6; the angle between the fast axis direction of the second half-wave plate 12 and the x-axis is π / 8; the angle between the fast axis direction of the second 1 / 4 wave plate 15 and the x-axis is π / 4.

[0017] Working principle: Linear polarization laser 1 emits linear polarization light, which enters orthogonal polarization beam generation module 17 through speckle attenuator 2, first half-wave plate 3 and beam expansion system 4 in sequence; after entering orthogonal polarization beam generation module 17, linear polarization light is divided into p-polarization light and s-polarization light by first polarization beam splitter 8, p-polarization light and s-polarization light are respectively combined to form orthogonal polarization laser light after being acted upon by corresponding first 1 / 4 wave plate 9 and first reflector 10, and orthogonal polarization laser light is emitted to the rotating bearing roller to be measured on the object turntable 7, and the orthogonal polarization laser light reflected by the bearing roller to be measured enters receiving end 18, is received by imaging lens 11, and then successively passes through second half-wave plate 12 and beam splitter 13 to become reflected light and transmitted light, and the transmitted light enters second polarization beam splitter 14 to become first p-polarization light and the first s-polarized light, the first p-polarized light and the first s-polarized light enter the corresponding line array camera 19 respectively; the reflected light enters the third polarization beam splitter 16 after passing through the second 1 / 4 wave plate 15 and becomes the second p-polarized light and the second s-polarized light, the second p-polarized light and the second s-polarized light enter the corresponding line array camera 19 respectively, and then the four groups of line array cameras 19 capture the π / 2 four-step phase-shifted fringe pattern, and the computer obtains the four-step phase-shifted fringe pattern for analyzing and obtaining the surface information of the bearing roller to be tested. Combined with polarization interference and line scanning fringe imaging strategies, the problems of traditional surface structured light projection under defocus and high reflection conditions are effectively solved, and at the same time, the shortcomings of traditional interference technology with small detection range and sensitivity to background light, environmental vibration, and temperature and humidity changes can be overcome, so as to achieve a wider range of application scenarios.

[0018] The imaging lens receives two beams of orthogonally polarized laser light from the bearing roller to be tested, and the Jones matrices thereof are:

[0019]

[0020] In the formula, B V , B H is the Jones matrix expression of orthogonally polarized laser beams, is the phase difference between the two beams;

[0021] The fast axis of the second half-wave plate is placed at a position π / 8 from the x-axis, and its Jones matrix is:

[0022]

[0023] The reflection Jones matrix and transmission Jones matrix after passing through the beam splitter are:

[0024]

[0025] In the formula, r s ,t s is the amplitude reflection coefficient and amplitude transmission coefficient of the beam splitter for s-polarized light, r p ,t pare the amplitude reflection coefficient and amplitude transmission coefficient of the beam splitter for p-polarized light;

[0026] The reflection and transmission Jones matrices of the second polarization beam splitter are:

[0027]

[0028] The fast axis direction of the second quarter wave plate is 45 degrees to the x-axis, and its Jones matrix is:

[0029]

[0030] The combined Jones matrix irradiated onto the linear array camera CCD1 is:

[0031]

[0032] The two beams on the linear array camera CCD1 are obtained as follows:

[0033]

[0034]

[0035] The two light beams irradiated on the linear array cameras CCD2-CCD4 are deduced in the same way, and the light intensity on the linear array cameras CCD1-CCD4 is obtained as follows:

[0036]

[0037]

[0038]

[0039]

[0040] Calculate the wrapped phase value based on the above light intensity:

[0041]

[0042] The phase value of the wrapped phase is [-π,π], and the subsequent unwrapping process is used to obtain the continuous phase. The 3D spatial information of the target imaging surface is obtained by combining the calibration parameters, and then the spatial curvature, 3D depth information, roughness and other parameters are calculated; at the same time, the surface intensity image of the bearing roller to be tested is obtained by superposition and averaging the π / 2 four-step phase-shifted fringe pattern, and additional information such as its modulation degree and phase quality map can also be calculated; the Jones matrix theory is used to analyze and describe the polarization state and interaction of the light beam, which helps to accurately control and predict the behavior of the light beam in the optical path, and provide a theoretical basis for experimental design and optimization.

[0043] In addition, the utility model ensures the light quality while reducing the interference of background light and speckle noise through the adjustment of reflected and transmitted light by the first half-wave plate, the second half-wave plate, and the beam splitter, and the light selection by each polarization beam splitter, thereby improving the imaging quality.

[0044] The above embodiments only express the implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. In this embodiment, up, down, left, right, front, and back only represent their relative positions and do not represent their absolute positions. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A bearing roller appearance line scanning fringe detection device based on polarization interference, characterized in that: The invention comprises a transmitting end (20) and a receiving end (18); the transmitting end (20) comprises a linear polarization laser (1), and an orthogonal polarization beam generating module (17) and a linear diffusion plate (6) are sequentially arranged in the laser emission direction of the linear polarization laser (1); the receiving end (18) comprises an imaging lens (11), and the imaging lens (11) is sequentially provided with a second half-wave plate (12) and a beam splitter (13) along the laser transmission direction, and a second polarization beam splitter (14) and a third polarization beam splitter (16) are respectively arranged in the transmission and reflection directions of the beam splitter (13); and linear array cameras (19) are respectively arranged in the polarization light path directions of the second polarization beam splitter (14) and the third polarization beam splitter (16).

2. The device for detecting the appearance line scan stripes of a bearing roller based on polarization interference according to claim 1 is characterized in that: The orthogonal polarized light beam generating module (17) comprises a first polarization beam splitter (8) for receiving laser light emitted by a linear polarization laser (1), and a first quarter wave plate (9) and a first reflector (10) are provided in both the p-polarized light path direction and the s-polarized light path direction of the first polarization beam splitter (8).

3. The device for detecting the appearance line scan stripes of a bearing roller based on polarization interference according to claim 1 is characterized in that: A speckle attenuator (2) is arranged in front of the linear polarization laser (1).

4. The device for detecting the appearance line scan stripes of a bearing roller based on polarization interference according to claim 3 is characterized in that: A first half-wave plate (3) is arranged in front of the speckle attenuator (2).

5. The device for detecting the appearance line scan stripes of a bearing roller based on polarization interference according to claim 4 is characterized in that: A beam expansion system (4) is arranged in front of the first half-wave plate (3).

6. The device for detecting the appearance line scan stripes of a bearing roller based on polarization interference according to claim 1 is characterized in that: The linear polarization laser (1) is a single-mode laser.

7. The device for detecting the appearance line scan stripes of a bearing roller based on polarization interference according to claim 1 is characterized in that: A second reflector (5) is provided between the orthogonal polarized light beam generating module (17) and the linear diffuser (6); the incident direction of the second reflector (5) is toward the first polarized beam splitter (8), and the reflection direction of the second reflector (5) is toward the linear diffuser (6).

8. The device for detecting the appearance line scan stripes of a bearing roller based on polarization interference according to claim 1 is characterized in that: A second quarter wave plate (15) is provided between the beam splitter (13) and the third polarization beam splitter (16).

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