CN117190880A - Laser displacement sensor and control method thereof - Google Patents

Abstract

The application discloses a laser displacement sensor and a control method thereof, wherein the laser displacement sensor comprises an illumination module, a photosensitive imaging module and a control processing module; the laser emergent assembly of the lighting module is used for emergent laser detection beams; the optical path modulation component comprises a cylinder, the cylinder rotates around the center of the cylinder at a preset angular speed, and the reflecting surface of the cylinder is used for changing the position of the laser detection beam irradiated on the center of a light spot of the measured object; the photosensitive imaging module is used for collecting a single-frame photosensitive image of the measured object; the control processing module determines the displacement of the measured object based on the center of the single-frame photosensitive image. The laser displacement sensor has the advantages of being compact in structure and convenient to integrate and mass produce.

Description

Laser displacement sensor and control method thereof

Technical Field

The embodiment of the application relates to the technical field of high-precision detection, in particular to a laser displacement sensor and a control method thereof.

Background

At present, a laser displacement sensor generally uses the principle of a triangular reflection method, namely, laser beams emitted by a laser diode irradiate the surface of a measured object, and reflected light rays are projected onto a photosensitive element matrix through a group of lenses. According to the difference of the distance between the surface of the measured object and the laser light source, the imaging position on the photosensitive element matrix is also different, and the surface displacement of the measured object can be confirmed by calculating the center of the photosensitive image on the photosensitive element matrix.

The displacement measured value of the technology is in corresponding relation with the center of the photosensitive image, so that the measurement accuracy is greatly influenced by the quality of the photosensitive image. However, because the laser is a coherent light source, the laser speckle effect is inevitably brought, that is, when the coherent light irradiates the measured object, different optical path differences are caused by reflection or scattering of the incident coherent light by different surface elements, and the reflected or scattered light waves generate interference phenomena when meeting in space, so that spots with random and irregular light intensity distribution can be formed on the surface of the measured object. The laser speckle effect can cause deformation of a photosensitive image, influence calculation of the center of the photosensitive image, and further influence measurement accuracy of a laser displacement sensor.

Disclosure of Invention

The application provides a laser displacement sensor and a control method thereof, which have the advantages of compact structure and convenience in integration and mass production, and can inhibit the laser speckle effect and greatly improve the measurement accuracy of the laser displacement sensor.

In a first aspect, the application provides a laser displacement sensor, comprising an illumination module, a photosensitive imaging module and a control processing module;

the illumination module comprises a laser emergent assembly and an optical path modulation assembly; the laser emergent assembly is used for emergent laser detection beams; the light path modulation component comprises a cylinder which can rotate around the center of the cylinder at a preset angular speed; the side wall of the cylinder is a reflecting surface, the reflecting surface is positioned on the optical axis of the laser detection beam, and the reflecting surface is used for changing the position of the laser detection beam irradiated on the center of a light spot of the measured object;

the photosensitive imaging module is positioned on the propagation path of the laser detection beam reflected by the detected object and is used for receiving the laser detection beam and obtaining a single-frame photosensitive image of the detected object according to the laser detection beam;

the control processing module is connected with the photosensitive imaging module; and the control processing module acquires the displacement of the measured object based on the center of the single-frame photosensitive image.

Optionally, the light path modulation component further comprises an illumination lens; the illumination lens is located on a propagation path of the laser probe beam reflected by the reflection surface.

Optionally, the reflective surface includes a plurality of reflective particles or a plurality of microlenses.

Optionally, the laser emitting component and the measured object are respectively located at two sides of a normal line of the tangential plane of the reflecting point on the reflecting surface.

Optionally, the optical path modulation assembly further includes a driving device connected to the cylinder and the control processing module, respectively, for driving the cylinder to rotate around its center at a preset angular speed according to a control signal of the control processing module.

Optionally, the driving means comprises a microelectromechanical system or a mechanical motor.

Optionally, the photosensitive imaging module comprises an imaging lens and a photosensitive element; the imaging lens and the photosensitive element are sequentially positioned on the propagation path of the laser detection beam reflected by the measured object;

the imaging lens is used for receiving the laser detection beam and projecting the laser detection beam onto the photosensitive element;

the photosensitive element is used for receiving the laser detection light beam and obtaining a single-frame photosensitive image of the surface of the measured object according to the laser detection light beam.

Optionally, the surface of the object to be measured, the imaging lens and the photosensitive surface of the photosensitive element intersect on the same straight line.

Optionally, the control processing module comprises a driving circuit and an information processor;

the driving circuit is in communication connection with the driving device and is used for outputting a control signal to the driving device so as to control the driving device to drive the cylinder to rotate around the central axis of the cylinder at a preset angular speed;

the information processor is in communication connection with the photosensitive element and is used for determining displacement of an object to be detected according to the center of the single-frame photosensitive image.

In a second aspect, an embodiment of the present application further provides a control method for a laser displacement sensor, configured to control the laser displacement sensor provided in the first aspect, where the control method includes:

controlling the cylinder to rotate around the center of the cylinder at a preset angular speed, and changing the center position of the laser detection beam reaching the surface of the measured object by using the reflecting surface;

acquiring a single-frame photosensitive image of the laser detection beam carrying detection information of the detected object on the photosensitive element;

determining the center of the single-frame photosensitive image according to the single-frame photosensitive image;

and determining the displacement of the object to be detected according to the center of the single-frame photosensitive image.

In summary, the laser displacement sensor provided by the application has the advantages that the light path modulation component is arranged on the light emitting path of the laser emission component, the light path modulation component comprises a rotary cylinder, the reflection surface of the cylinder continuously reflects the laser detection light beam to irradiate the surface of the measured object M in the exposure time of the photosensitive imaging module, the effect of light homogenizing can be achieved, the speckle characteristics of the light spot irradiated by the laser detection light beam on the surface of the measured object at different moments in the exposure time of the image are different and random, the single-frame photosensitive image acquired by the photosensitive imaging module is an image formed after speckle suppression, the calculation precision of the speckle center of the single-frame photosensitive image is improved, the smoothness of speckle particles is realized, and finally the measurement precision of the laser displacement sensor is improved.

Drawings

FIG. 1 is a schematic diagram of a laser displacement sensor according to the present application;

FIG. 2 is a schematic diagram of an application of a laser displacement sensor according to the present application;

FIG. 3 is a schematic diagram of another laser displacement sensor according to the present application;

FIG. 4 is a schematic diagram of a control method of a laser displacement sensor according to the present application;

the drawings are as follows:

1. a lighting module; 11. a laser emitting assembly; 12. an optical path modulation component; 120. a cylinder; 130 an illumination lens; 121. a reflective surface.

2. A photosensitive imaging module; 21. an imaging lens; 22. a photosensitive element.

3. And a control processing module.

Detailed Description

The application is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the application and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present application are shown in the drawings.

The present application is directed to a laser displacement sensor in view of one or more of the above-mentioned problems occurring in the prior art. Fig. 1 is a schematic structural diagram of a laser displacement sensor provided by the application. Referring to fig. 1, a laser displacement sensor provided by an embodiment of the present application includes an illumination module 1, a photosensitive imaging module 2, and a control processing module 3; the illumination module 1 comprises a laser emitting assembly 11 and an optical path modulation assembly 12; the laser emitting assembly 11 is used for emitting laser detection light S; the optical path modulating assembly 12 includes a cylinder 120, the cylinder 120 rotating about its center axis o at a preset angular velocity ω; the side wall of the cylinder 120 is a reflecting surface 121, the reflecting surface 121 is positioned on the optical axis of the laser detection light S, and the reflecting surface 121 is used for changing the position of the laser detection light S irradiated on the spot center of the measured object M; the photosensitive imaging module 2 is positioned on the propagation path of the laser detection light S reflected by the measured object M and is used for receiving the laser detection light S and obtaining a single-frame photosensitive image of the measured object M according to the laser detection light S; the control processing module 3 is connected with the photosensitive imaging module 2; the control processing module 3 acquires the displacement of the object M to be measured based on the center of the single frame photosensitive image.

Specifically, as shown in fig. 1, the laser emitting assembly 11 of the illumination module 1 may employ a semiconductor laser to emit the laser probe beam S. By way of example, a semiconductor laser in the visible light band, such as 760nm red semiconductor laser, has the advantage of good monochromaticity and high brightness. The optical path modulation component 12 is sequentially arranged on the propagation path of the laser detection beam S, and the optical path modulation component 12 can adjust the propagation direction of the laser detection beam S. The optical path modulating element 12 includes a cylinder 120 rotatable about a central axis o at a predetermined angular velocity ω. In this embodiment, the cylinder 120 is rotated counterclockwise as shown in the figure, and the preset angular velocity ω may be a constant value or a variable value. The side wall of the cylinder 120 is a reflecting surface 121, and the reflecting surface 121 is a ring surface and is located on the optical axis of the laser detection light S. In the counterclockwise rotation direction, there are a plurality of continuous reflection points on the reflection surface 121, for example, as the reflection point a and the reflection point b, only the reflection of the laser probe beam S by the reflection point b on the reflection surface 121 is shown in fig. 1, and it should be noted that, in consideration of the process error, it is difficult to make the reflection point a and the reflection point b of the reflection surface 121 identical, and there are fine differences on the surfaces of the reflection point a and the reflection point b of the reflection surface 121, which are process errors, such as uneven surfaces of the reflection surface, coarse particles, and the like. Since the cylinder 120 rotates, the laser detection beam S irradiates the surface of the measured object M after being reflected by the reflection point a and the reflection point b of the reflection surface 121 in sequence in a continuous time, and when there is a fine difference between the reflection point a and the reflection point b of the reflection surface 121, there is a fine difference in the spot center position of the laser detection beam S irradiated on the surface of the measured object M; it can be understood that the laser probe beam S continuously reflects to the surface of the measured object M through the rotating reflecting surface 121, and the speckle characteristics of the light spot irradiated by the laser probe beam S on the surface of the measured object M at different times are different and random, so as to play a role of uniform light.

When the displacement measurement is carried out on the measured object M, the photosensitive surface of the photosensitive imaging module 2 receives the laser detection light beam S reflected by the measured object M, and as the speckle characteristics of the light spots irradiated on the surface of the measured object M by the laser detection light beam S at different times are different and random, the interference effect of the reflected or scattered light on the surface of the measured object M can be reduced, and the effect of inhibiting the laser speckle is achieved; in the photosensitive imaging exposure time of the photosensitive imaging module 2, the gray value of each pixel is the integral of the speckle characteristics of the surface of the measured object M at different moments, so that the single-frame photosensitive image actually collected in each exposure time of the photosensitive imaging module 2 is an image formed after speckle suppression.

The control processing module 3 extracts the single-frame photosensitive image obtained by the photosensitive imaging module 2, and performs spot center calculation based on the single-frame photosensitive image after speckle suppression to obtain the center of the single-frame photosensitive image in the exposure time; when the measured object M is displaced, in a new exposure time, the photosensitive imaging module 2 can obtain a new single-frame photosensitive image after speckle suppression, the control processing module 3 re-extracts the single-frame photosensitive image obtained by the photosensitive imaging module 2, and performs spot center calculation based on the single-frame photosensitive image after speckle suppression to obtain a center of the single-frame photosensitive image in the new exposure time, and further confirms the displacement of the measured object M according to the center position difference of the obtained single-frame photosensitive image. Because the laser speckle is restrained in the exposure time of each single-frame photosensitive image, the calculation precision of the facula center of the single-frame photosensitive image is higher, and finally the measurement precision is improved. The single frame photosensitive image refers to an image formed by the surface of the measured object M in the photosensitive imaging module 2.

In summary, the laser displacement sensor provided by the application has the advantages that the light path modulation component is arranged on the light emitting path of the laser emergent component, the light path modulation component comprises the rotary cylinder, the reflection surface of the cylinder is utilized to continuously reflect the laser detection light beam to irradiate the surface of the measured object M in the exposure time of the photosensitive imaging module, the effect of light homogenizing can be achieved, the speckle characteristics of the laser detection light beam irradiated on the surface of the measured object at different moments in the single-frame exposure time of the image are different and random, the single-frame photosensitive image acquired by the photosensitive imaging module is an image formed after speckle suppression, the calculation precision of the speckle center of the single-frame photosensitive image is improved, the smoothness of speckle particles is realized, and the measurement precision of the laser displacement sensor is finally improved.

Optionally, as further shown in fig. 1, the laser emitting assembly 11 and the measured object M are respectively located at two sides of the normal line of the tangential plane of the incident point of the reflecting surface 121. With this arrangement, it is ensured that the laser probe beam S emitted from the laser emitting assembly 11 is reflected by the reflection point on the reflection surface 121 and then irradiates the surface of the measured object M.

With continued reference to fig. 1, one possible embodiment, the optical path modulation assembly 12 further includes an illumination lens 130; the illumination lens 130 is located on the propagation path of the laser probe light S reflected by the reflection surface 121.

Specifically, the cylinder 120 may also be referred to as a circular cylindrical mirror, and the sidewall of the cylinder 120 is a reflecting surface 121, and in practical application, in consideration of process errors, there is an unavoidable difference in roundness of the sidewall cross section of the cylinder, where the roundness difference is a process error, and in the embodiment of the present application, the roundness difference of the cylinder is within an acceptable range. The laser detection beam S continuously reflects through the rotating reflecting surface 121 and irradiates onto the surface of the measured object M after being condensed by the illumination lens 130, and because of the fine difference between the surfaces of the reflecting point a and the reflecting point b, fine jitter exists in the spot center of the laser detection beam S irradiated onto the surface of the measured object M at different moments, the speckle characteristics of the spot on the surface of the measured object M at different moments are different and random, thereby playing a role of uniform light, and a single-frame photosensitive image after speckle suppression is obtained by integrating the speckle characteristics of the surface of the measured object M in the exposure time of the photosensitive imaging module 2.

The roundness refers to the degree that the cross section of a workpiece is close to a theoretical circle, when the difference between the maximum radius and the minimum radius is 0, the roundness is 0, and the measuring tool is a roundness measuring instrument and is used for measuring the roundness of an annular workpiece.

Optionally, the reflective surface 121 includes a plurality of reflective particles or a plurality of microlenses.

Specifically, in order to further improve the light uniformity characteristic of the reflecting surface 121, a plurality of uniformly distributed reflective particles or a plurality of uniformly distributed microlenses may be added on the surface of the reflecting surface 121, the reflective particles may be metal ions or inorganic nonmetallic particles, the microlenses may be a microlens array with smaller size, and the like, and it is emphasized that the sizes of the reflective particles and the microlenses need to be controlled so as to slightly adjust the sizes of the reflective particles and the microlenses to irradiate the central position of the spot on the surface of the measured object M, and in a feasible implementation, the sizes of the reflective particles and the microlenses are set to be in the μm (micrometer) level, or in the nm (nanometer) level, or smaller, and in the exposure time, the uniform irradiation of the laser probe beam S on the surface of the measured object M may be satisfied, so as to perform the light uniformity function.

FIG. 2 is a schematic diagram of an application of a laser displacement sensor according to the present application; fig. 3 is a schematic diagram of another application of the laser displacement sensor provided by the application. Wherein the driving means in fig. 2 and 3 are not shown. Alternatively, as shown in conjunction with fig. 2 and 3, the photosensitive imaging module 2 includes an imaging lens 21 and a photosensitive element 22; the imaging lens 21 and the photosensitive element 22 are sequentially positioned on the propagation path of the laser detection light S reflected by the object M to be measured; the imaging lens 21 is configured to receive the laser detection light S and project the laser detection light S onto the photosensitive element 22; the photosensitive element 22 is configured to receive the laser detection light S, and obtain a single-frame photosensitive image of the surface of the measured object M according to the laser detection light S.

Specifically, as shown in fig. 2 and 3, the imaging lens 21 and the photosensitive element 22 form an imaging system, the imaging lens 121 is used for converging the laser probe beam S reflected by the measured object M, and the photosensitive element 21 may be a high-width photosensitive matrix. For example, a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor or a CCD (charge coupled device, CCD) image sensor is employed.

Specifically, in practical applications, the surface of the object M that appears to be flat may find some fine irregularities after enlargement, and these fine irregularities often cause measurement errors when using conventional focused spot type sensors. The application adopts the photosensitive element 21 with larger size, and generates a single-frame photosensitive image by increasing the photosensitive surface and more receiving the laser detection light beam S reflected by the surface of the measured object M, thereby improving the utilization rate of reflected light, reducing the influence of uneven homogenized surface of the measured object M, and realizing stable measurement even on a rough object, thereby improving the accuracy of measurement.

Alternatively, as shown in fig. 2 and 3, the surface of the object M to be measured, the imaging lens 21 and the photosensitive surface of the photosensitive element 22 are disposed to intersect in the same straight line, to form a magneto-optical system, the light sensing amount of the laser detection beam S reflected by the measured object M irradiated on the light sensing element 21 can be improved, the influence of uneven surface of the measured object is reduced, stable measurement is realized, and the measurement accuracy is improved.

On the basis of the above-described embodiment, as shown in connection with fig. 1 to 3, the optical path modulation assembly 12 further comprises driving means (not shown in the figures) respectively connected to the cylinder 120 and the control processing module 3 for driving the cylinder 120 to rotate about its central axis o at a preset angular velocity ω according to the control signal of the control processing module 3. Among them, the driving device includes Micro-Electro-Mechanical System (MEMS) or mechanical motor, or other possible driving devices, etc.

Optionally, with continued reference to fig. 1-3, the control processing module 3 includes a drive circuit and an information processor; the driving circuit is in communication connection with the driving device and is used for outputting a control signal to the driving device so as to control the driving device to drive the cylinder 120 to rotate around the central axis o at a preset angular speed omega; the information processor is communicatively coupled to the photosensitive element 22 for determining displacement of the object under test based on the center of the single frame photosensitive image. The information processor can analyze and process the single-frame photosensitive image, extract and calculate the center of the single-frame photosensitive image, and has the functions of inhibiting laser speckle, mapping and outputting distance results and the like.

In summary, the laser displacement sensor provided by the application has the advantages of compact structure, convenience for integration and mass production by the optical structure of the laser, the circular cylindrical reflector and the high-width photosensitive system, can inhibit the laser speckle effect and greatly improve the measurement precision of the laser displacement sensor.

Based on the same inventive concept, the embodiment of the application also provides a control method of the laser displacement sensor, which is used for controlling the laser displacement sensor provided by the embodiment. Fig. 4 is a schematic diagram of a control method of a laser displacement sensor according to an embodiment of the present application. Referring to fig. 1 to fig. 4, a control method of a laser displacement sensor according to an embodiment of the present application includes:

s101, controlling the cylinder to rotate around the center of the cylinder at a preset angular speed, and changing the central position of the laser detection beam reaching the surface of the object to be detected by using the reflecting surface.

S102, acquiring a single-frame photosensitive image of a laser detection beam carrying detection information of the detected object on a photosensitive element.

S103, determining the center of the single-frame photosensitive image according to the single-frame photosensitive image.

S104, determining the displacement of the object to be detected according to the center of the single-frame photosensitive image.

Specifically, as shown in fig. 1-3, after measurement is started, the laser emitting component 11 emits a laser detection beam S, and as shown in fig. 2 and 3, the cylinder 120 rotates clockwise around the central axis O, the laser detection beam S is reflected by the reflecting surface 121 of the cylinder 120 that rotates continuously, and then irradiates on the first position (1) of the measured object M through the illumination lens 130, after the laser detection beam S reflects by the reflecting surface 121 that rotates continuously, the spot center position of the laser detection beam S irradiated on the surface of the measured object M is slightly changed, during the exposure time of image acquisition, the continuously rotating reflecting surface 121 can play a role of uniform light, the spot speckle characteristics of the laser detection beam S irradiated on the surface of the measured object M are different and random, the photosensitive surface of the photosensitive imaging module 2 receives the laser detection beam S reflected by the surface of the measured object M, and generates a single-frame image of the measured object M at the first position (1), the gray value of each pixel in the single-frame image is the integral of the surface speckle characteristic of the measured object M at different moments, thereby increasing the statistics of the photosensitive data of the single-frame image and the random statistics data; the information processor extracts and calculates the pixel gray value of the single frame photosensitive image, and determines the center of the single frame photosensitive image of the measured object M as the first position (1) by the pixel gray value size on the photosensitive element 21.

When the measured object M moves to the second position (2), the cylinder 120 continuously rotates, the laser detection beam S continuously reflects off the reflecting surface 121, and irradiates on the surface of the measured object M through the illumination lens 130, the reflecting surface 121 slightly changes the spot center position of the laser detection beam S irradiated on the surface of the measured object M, and during the exposure time of image acquisition, the photosurface of the photosensitive element 21 continuously acquires the laser detection beam S reflected on the surface of the measured object M, and the spot speckle characteristics of the laser detection beam S at different moments are different and random, and the photosensitive element 21 generates a single-frame photosensitive image of the measured object M at the second position (2), so that the data statistics data amount and the data statistics randomness of the single-frame photosensitive image are increased; the information processor extracts and calculates the pixel gray value of the single frame photosensitive image, and determines the center of the single frame photosensitive image of the measured object M as the second position (2) on the photosensitive element 21 by the pixel gray value size. Wherein, the single frame photosensitive images of the measured object M generated by the photosensitive element 21 at the first position (1) and the second position (2) are images after speckle suppression.

The information processor analyzes and processes the center offset of the first position (1) and the second position (2), for example, calculates the coordinate difference value of the first position (1) and the second position (2) of the photosensitive element 21, records the coordinate difference value as the center offset of the single-frame photosensitive image, the photosensitive element 21 is a high-width photosensitive matrix, the center offset of the single-frame photosensitive image and the moving distance of the measured object M have a preset mapping relation, and the information processor outputs the displacement of the measured object M in a mapping way according to the center offset of the single-frame photosensitive image.

In summary, the application adds a cylinder on the optical axis of the laser detection beam, and utilizes the reflecting surface of the cylinder which continuously rotates to slightly adjust the spot center position of the laser detection beam irradiated on the surface of the measured object M to play a role of uniform light, thereby leading the spot speckle characteristics of the laser detection beam irradiated on the surface of the measured object M at different moments to be different and random in the image exposure time, leading the single frame photosensitive image obtained by the photosensitive imaging module to be an image formed after speckle suppression, being beneficial to improving the spot center calculation precision of the single frame photosensitive image, realizing the smoothness of speckle particles and finally improving the measurement precision of the laser displacement sensor

Note that the above is only a preferred embodiment of the present application and the technical principle applied. It will be understood by those skilled in the art that the present application is not limited to the particular embodiments described herein, and that various obvious changes, rearrangements, combinations, and substitutions can be made by those skilled in the art without departing from the scope of the application. Therefore, while the application has been described in connection with the above embodiments, the application is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the application, which is set forth in the following claims.

Claims (10)

1. The laser displacement sensor is characterized by comprising an illumination module, a photosensitive imaging module and a control processing module;

the illumination module comprises a laser emergent assembly and an optical path modulation assembly; the laser emergent assembly is used for emergent laser detection beams; the light path modulation component comprises a cylinder which can rotate around the center of the cylinder at a preset angular speed; the side wall of the cylinder is a reflecting surface, the reflecting surface is positioned on the optical axis of the laser detection beam, and the reflecting surface is used for changing the position of the laser detection beam irradiated on the center of a light spot of the measured object;

the photosensitive imaging module is positioned on the propagation path of the laser detection beam reflected by the detected object and is used for receiving the laser detection beam and obtaining a single-frame photosensitive image of the detected object according to the laser detection beam;

the control processing module is connected with the photosensitive imaging module; and the control processing module acquires the displacement of the measured object based on the center of the single-frame photosensitive image.

2. The laser displacement sensor of claim 1, wherein the optical path modulation assembly further comprises an illumination lens;

the illumination lens is located on a propagation path of the laser probe beam reflected by the reflection surface.

3. The laser displacement sensor of claim 1, wherein the reflective surface comprises a plurality of reflective particles or a plurality of microlenses.

4. The laser displacement sensor of claim 1, wherein the laser exit assembly and the object are located on opposite sides of a normal to a tangential plane of a reflection point on the reflecting surface.

5. The laser displacement sensor of claim 1, wherein the optical path modulation assembly further comprises a driving device respectively connected to the cylinder and the control processing module for driving the cylinder to rotate at a preset angular velocity about its center axis according to a control signal of the control processing module.

6. The laser displacement sensor of claim 5, wherein the driving means comprises a microelectromechanical system or a mechanical motor.

7. The laser displacement sensor of claim 1, wherein the photosensitive imaging module comprises an imaging lens and a photosensitive element; the imaging lens and the photosensitive element are sequentially positioned on the propagation path of the laser detection beam reflected by the measured object;

the imaging lens is used for receiving the laser detection beam and projecting the laser detection beam onto the photosensitive element;

the photosensitive element is used for receiving the laser detection light beam and obtaining a single-frame photosensitive image of the surface of the measured object according to the laser detection light beam.

8. The laser displacement sensor according to claim 7, wherein the surface of the object to be measured, the imaging lens, and the photosensitive surface of the photosensitive element intersect on the same straight line.

9. The laser displacement sensor of claim 7, wherein the control processing module comprises a drive circuit and an information processor;

the driving circuit is in communication connection with the driving device and is used for outputting a control signal to the driving device so as to control the driving device to drive the cylinder to rotate around the central axis of the cylinder at a preset angular speed;

the information processor is in communication connection with the photosensitive element and is used for determining displacement of an object to be detected according to the center of the single-frame photosensitive image.

10. A control method of a laser displacement sensor for controlling the laser displacement sensor according to any one of claims 1 to 9, the control method comprising:

controlling the cylinder to rotate around the center of the cylinder at a preset angular speed, and changing the center position of the laser detection beam reaching the surface of the measured object by using the reflecting surface;

acquiring a single-frame photosensitive image of the laser detection beam carrying detection information of the detected object on the photosensitive element;

determining the center of the single-frame photosensitive image according to the single-frame photosensitive image;

and determining the displacement of the object to be detected according to the center of the single-frame photosensitive image.