A laser velocimetry method and device for a group of particles

Abstract

The application provides a laser velocity measuring device for particle groups, comprising a fiber installation frame, a multi-laser emitting device, a multi-laser receiving device and a particle emitting device; a plurality of groups of parallel distributed light curtain installation frames are arranged on the fiber installation frame, and optical fibers are installed on the light curtain installation frames; the optical fibers comprise input optical fibers and output optical fibers; one end of the input optical fibers is connected with the multi-laser emitting device, and the other end is installed on one side of the light curtain installation frame; one end of the output optical fibers is connected with the multi-laser receiving device, and the other end is installed on the other side of the light curtain installation frame; the particle emitting device is arranged on one side of the fiber installation frame, and the particle group emitting direction is perpendicular to the light curtain; and the application further provides a laser velocity measuring method for particle groups. The application realizes the measurement of the particle cloud movement velocity vector and trajectory, can conveniently and flexibly adjust the distance between laser beams to measure the trajectories of the maximum number of particles, and has the advantages of simple operation, low cost and strong practicability.

Description

Technical fields:

[0001] This invention belongs to the field of three-dimensional measurement technology for high-speed particle group motion, specifically relating to a laser velocimetry method and device for particle groups. Background technology:

[0002] When aircraft take off and land or traverse dusty airspace, aero engines often ingest small particles such as sand, and these particles are often ingested in groups. Since engine impellers can rotate at speeds of tens of thousands of revolutions per minute, the impact of these particles can cause damage to the blade surfaces. This impact damage creates stress concentrations in localized areas of the structure, leading to a series of subsequent problems such as reduced residual strength, decreased fatigue life, and altered dynamic characteristics, threatening the safety of the aircraft.

[0003] Impact damage encountered by engines during actual service can only be observed during maintenance after aircraft landing. To simulate the impact of particle clouds that engine rotor blades may encounter under laboratory conditions, current methods such as air guns, wind tunnels, and rotating nozzles are commonly used to provide velocity data for the particle swarm. However, the velocity of the particle cloud is often estimated using certain assumptions. To obtain the actual velocity distribution characteristics of the particle swarm motion, a three-dimensional velocimetry method and device capable of acquiring particle swarm motion information is needed. Currently, mainstream velocimetry methods for particle motion include digital imaging, laser speckle, and transmission methods. However, these methods mostly only obtain two-dimensional velocity fields of the particles and are very expensive.

[0004] Therefore, it is necessary to provide a particle cloud laser velocimetry device and method to realize the measurement of particle swarm velocity. Summary of the Invention:

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a laser velocimetry method and apparatus for particle groups, enabling the measurement of the velocity and trajectory of particle groups.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] (I) This invention provides a laser velocimetry method for particle swarms, comprising the following steps:

[0008] S1. Set the speed measurement zone: This invention targets particle swarms whose motion direction is approximately perpendicular to the light curtain. Since the lateral velocity of these particle swarms is relatively small, this invention only sets v... x ,v y The lower limit;

[0009] S2. Activate the data acquisition device and particle emission device. The particle swarm emitted by the particle emission device passes through three light curtains.

[0010] S3. Process the time-domain signals obtained from each channel of the data acquisition device one by one, and convert the acquired time-domain signals into an array of time points corresponding to the peak values ​​of the sensor trigger potentials, such as x located in the k-th light curtain. i If the photoelectric sensor at a certain location is triggered m times, then the recorded information is:

[0011] S4, the first light curtain and In t L1 The time when it is triggered is denoted as X1, Y1, and T1;

[0012] S5, the t collected by the second light curtain L2 >t L1 In the process, multiple locations where the second light curtain was triggered and their corresponding time points were found, forming a dataset. in

[0013] S6, t collected by the third light curtain L3 >t L1 In the process, multiple trigger locations and their corresponding time points are identified, forming a dataset. in

[0014] S7, Calculate the dataset S L2 The modulus of the vector corresponding to each element in the vector The smallest modulus As candidates, and denoted as X2, Y2, T2, if in dataset S L3 If an element can be found that satisfies equations (1) and (2), then the three data points are considered to correspond to the same particle, and the trigger position and time are recorded as X3, Y3, T3. Otherwise, the second smallest value is taken in the second light curtain, and so on until the above requirements are found. If the requirements are not found, then the particle is considered not to have been captured by the second or third light curtain, and the velocity measurement of the particle is abandoned.

[0015]

[0016]

[0017] Where g is the acceleration due to gravity; c d The drag coefficient is taken as 0.47; ρ air air density; ρ ρ Particle density; l Lazer The distance between the light curtains;

[0018] S8. Repeat S5 to S7 for all trigger signals detected by the first light curtain, and match the signals detected by the second and third light curtains.

[0019] S9. For the particles that were successfully matched in the previous step, calculate the velocity of each particle:

[0020]

[0021] Furthermore, in order to prevent a single particle from simultaneously triggering two laser beams while maintaining an 80% capture probability, the center spacing of the laser beams is increased by l. Gap Set to d Lazer +μ-σ, where d Lazer μ is the diameter of the laser beam, and d is the particle diameter. p The mean value, σ is the particle diameter d p The standard deviation.

[0022] Furthermore, the light curtain spacing

[0023] (II) The present invention also provides a laser velocimetry device for particle swarms, comprising an optical fiber mounting frame, a multi-channel laser emitting device, a multi-channel laser receiving device, and a particle emitting device; the optical fiber mounting frame is provided with several sets of parallel light curtain mounting frames, and optical fibers are installed on the light curtain mounting frames, the light beams generated by the optical fibers forming a light curtain; the optical fibers include input optical fibers and output optical fibers; one end of the input optical fiber is connected to the multi-channel laser emitting device, and the other end is installed on one side of the light curtain mounting frame; one end of the output optical fiber is connected to the multi-channel laser receiving device, and the other end is installed on the other side of the light curtain mounting frame; the positions of the input optical fibers and the output optical fibers correspond one-to-one; the particle emitting device is located on one side of the optical fiber mounting frame, and its particle swarm emission direction is perpendicular to the light curtain.

[0024] Furthermore, several groups of input optical fibers are arranged and installed in parallel on the left / right and top / bottom sides of the light curtain mounting frame; the number of output optical fibers is the same as the number of input optical fibers, and they are installed in parallel on the right / left and bottom / top sides of the light curtain mounting frame; the input optical fibers on the left / right and top / bottom sides are respectively connected to two groups of multi-channel laser emitting devices, and the output optical fibers on the right / left and bottom / top sides are respectively connected to two groups of multi-channel laser receiving devices.

[0025] Furthermore, the light curtain mounting frame is slidably installed inside the fiber optic mounting frame to adjust the distance between two adjacent light curtain mounting frames; the fiber optic mounting frame is provided with an upper slide rail and a lower slide rail, and the upper and lower edges of the light curtain mounting frame are respectively provided with upper sliders and lower sliders that are adapted to the upper slide rail and the lower slide rail; the light curtain mounting frame is slidably connected to the fiber optic mounting frame through the slide rail and the slider.

[0026] Furthermore, the light curtain mounting frame slides within the fiber optic mounting frame via a first driving device. The first driving device includes a first hinge, a first driving screw, and a first stop pin. The first driving screw is rotatably mounted on one side of the fiber optic mounting frame. One end of the first hinge is connected to the other side of the fiber optic mounting frame, and the other end of the first hinge is hinged to a first horizontal sleeve. The first horizontal sleeve has an internal thread adapted to the first driving screw, and the first driving screw is threadedly connected to the first horizontal sleeve. Each group of light curtain mounting frames is hinged to the first hinge. Rotation of the first driving screw causes the first horizontal sleeve to move horizontally relative to the first driving screw, thereby moving the connecting rods of the first hinge, and thus moving each group of light curtain mounting frames to adjust the distance between adjacent groups of light curtain mounting frames.

[0027] Furthermore, the end of the first drive screw is provided with a first rotating handle, and the first rotating handle is provided with a plurality of circumferentially distributed through holes, the inner diameter of which is not less than the outer diameter of the first stop pin; the optical fiber mounting frame is provided with a threaded hole adapted to the first stop pin, and the first stop pin is passed through the through hole of the first rotating handle and screwed into the threaded hole of the optical fiber mounting frame to achieve the stopping effect.

[0028] Furthermore, the optical fiber is movably mounted on the light curtain mounting frame; the light curtain mounting frame is provided with slide rails on all four sides, and a number of sliding supports are slidably mounted on the slide rails, with the optical fiber mounted on the sliding supports.

[0029] Furthermore, the sliding support slides along the slide rail via a second driving device. The second driving device includes a second hinge, a second driving screw, a second stop pin, and two sets of fixed supports. The two sets of fixed supports are respectively fixed to both ends of the slide rail. The second driving screw is rotatably mounted on one fixed support. One end of the second hinge is connected to the other fixed support, and the other end of the second hinge is hinged to a second horizontal sleeve. The second horizontal sleeve has an internal thread adapted to the second driving screw, and the second driving screw is threadedly connected to the second horizontal sleeve. Each set of sliding supports is hinged to the second hinge. Rotation of the second driving screw causes the second horizontal sleeve to move horizontally relative to the second driving screw, thereby moving the connecting rods of the second hinge, which in turn causes each set of sliding supports to slide, thus adjusting the distance between adjacent sets of optical fibers.

[0030] Furthermore, the end of the second drive screw is provided with a second rotating handle, and the second rotating handle is provided with a plurality of circumferentially distributed through holes, the inner diameter of which is not less than the outer diameter of the second stop pin; the fixed support is provided with a threaded hole adapted to the second stop pin, and the stop function is achieved by passing the second stop pin through the through hole of the second rotating handle and screwing it into the threaded hole of the fixed support.

[0031] The beneficial effects of this invention are:

[0032] (1) The present invention designs a laser velocimetry method for particle groups, which can measure the velocity vector and trajectory of particle cloud motion, obtain the actual velocity distribution characteristics of particle group motion, and is simple to operate, low in cost and highly practical.

[0033] (2) The laser velocimetry device for particle groups of the present invention has a simple structure and can flexibly and conveniently adjust the laser beam spacing and light curtain spacing according to the particle size in order to measure the trajectory of the maximum number of particles. It has high accuracy and high reliability. Attached image description:

[0034] Figure 1 This is a schematic diagram of the optical fiber mounting frame structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the light curtain mounting frame structure of the present invention;

[0036] Figure 3 This is a schematic diagram illustrating the relationship between the particle diameter and the laser beam diameter in this invention;

[0037] Figure 4 This is a schematic diagram of the laser light curtain of the present invention;

[0038] Figure 5 This is a circuit diagram of the device of the present invention;

[0039] Figure 6 This is a schematic diagram showing the connection between the light curtain mounting frame and the optical fiber mounting frame of the present invention;

[0040] Figure 7 This is a schematic diagram showing the connection between the sliding support, the light curtain mounting frame, and the fixed support of the present invention.

[0041] Figure 8 This is a schematic diagram of the structure of the first driving device of the present invention;

[0042] Figures 9-10 This is a schematic diagram of the structure of the second driving device of the present invention;

[0043] Figure 11 This is a schematic diagram of the first stop pin of the present invention;

[0044] The labels in the attached diagram are:

[0045] 1. Fiber optic mounting frame; 1-1. Upper slide rail; 1-2. Lower slide rail; 1-3. Upper slider; 1-4. Lower slider; 2. Light curtain mounting frame; 2-1. Slide rail; 2-2. Sliding support; 3. First hinge; 4. First drive screw; 5. First stop pin; 6. First horizontal sleeve; 7. First rotary handle; 8. Second hinge; 9. Second drive screw; 10. Second stop pin; 11. Fixed support; 12. Second horizontal sleeve; 13. Second rotary handle; 14. Flying particle; 15. Laser beam; 16. Photoelectric conversion device; 17. Multi-channel high-frequency signal acquisition card; 18. Computer; 19. Wire; 20. Output fiber optic cable. Detailed implementation method:

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example 1

[0048] This invention provides a laser velocimetry method for particle swarms, comprising the following steps:

[0049]

Step 1

[0050]

Step 2

[0051]

Step 3

[0052] [Step 4] In order to prevent a single particle from triggering two laser beams simultaneously and to maintain an 80% capture probability, the center spacing of the laser beams is increased by l. Gap Set to d Lazer +μ-σ.

[0053]

Step 5

[0054]

Step 6

[0055]

Step 7

[0056] [Step 8] The first light curtain and In t L1 The time points are triggered, denoted as X1, Y1, and T1.

[0057] [Step 9] The t collected by the second light curtain L2 >t L1 In the process, multiple locations where the second light curtain was triggered and their corresponding time points were found, forming a dataset. in

[0058] [Step 10] The t collected by the third light curtain L3 >t L1 In the process, multiple trigger locations and their corresponding time points are identified, forming a dataset. in

[0059]

Step 11

[0060]

[0061]

[0062] Where g is the acceleration due to gravity; c d The drag coefficient is taken as 0.47; ρ air air density; ρ p Particle density; l lazer This refers to the spacing between the light curtains.

[0063]

Step 12

[0064]

Step 13

[0065]

[0066] Example 2

[0067] Reference Figures 1-5 This invention provides a laser velocimetry device for particle swarms, comprising an optical fiber mounting frame 1, a multi-channel laser emitting device, a multi-channel laser receiving device, a particle emitting device (light gas cannon), several optical fibers, an amplifier circuit, a multi-channel high-frequency signal acquisition card, and a computer.

[0068] In this embodiment, three sets of parallel light curtain mounting frames 2 (forming a rectangular frame structure) are provided on the optical fiber mounting frame 1. Optical fibers are installed on the light curtain mounting frames 2, and the light beams generated by the optical fibers form a light curtain. The optical fibers include input optical fibers and output optical fibers. One end of the input optical fiber is connected to a multi-channel laser emitting device, and the other end is installed on one side of the light curtain mounting frame 2. One end of the output optical fiber is connected to a multi-channel laser receiving device, and the other end is installed on the other side of the light curtain mounting frame 2. The positions of the input optical fibers and the output optical fibers correspond one-to-one. The particle emitting device is located on one side of the optical fiber mounting frame 1, and its particle swarm emission direction is perpendicular to the light curtain.

[0069] In this embodiment, several groups of input optical fibers are arranged and installed in parallel on the left and lower sides of the light curtain mounting frame 2; the number of output optical fibers is the same as the number of input optical fibers, and they are installed in parallel on the right and upper sides of the light curtain mounting frame 2; the input optical fibers on the left and lower sides are respectively connected to two groups of multi-channel laser emitting devices, and the output optical fibers on the right and upper sides are respectively connected to two groups of multi-channel laser receiving devices.

[0070] In this device, the laser emitted by the multi-channel laser emitter forms a laser beam in the light curtain mounting frame 2 through the input optical fiber. Multiple sets of horizontal and vertical laser beams form a light curtain within the frame. The laser beam is transmitted to the multi-channel laser receiver through the output optical fiber. The multi-channel laser receiver is connected to a signal amplification circuit to amplify the signal. The amplified signal is acquired by a multi-channel high-frequency signal acquisition card. Finally, the acquired data is processed by a computer to calculate the speed.

[0071] Example 3

[0072] This invention provides a laser velocimetry device for particle groups. Its main structure is the same as that of Embodiment 2, except that the distance between the three sets of light curtain mounting frames 2 is adjustable in this embodiment.

[0073] Specifically, refer to Figures 1-11 In this embodiment, the light curtain mounting frame 2 is slidably installed inside the optical fiber mounting frame 1 to adjust the distance between two adjacent light curtain mounting frames 2; the optical fiber mounting frame 1 is provided with an upper slide rail 1-1 and a lower slide rail 1-2, and the upper and lower edges of the light curtain mounting frame 2 are respectively provided with an upper slider 1-3 and a lower slider 1-4 that are adapted to the upper slide rail 1-1 and the lower slide rail 1-2; the light curtain mounting frame 2 is slidably connected to the optical fiber mounting frame 1 through the slide rail and the slider.

[0074] In this embodiment, the light curtain mounting frame 2 slides within the optical fiber mounting frame 1 via a first driving device; the first driving device includes a first hinge 3, a first driving screw 4, and a first stop pin 5; the first driving screw 4 (via a bearing) is rotatably mounted on one side of the optical fiber mounting frame 1; one end of the first hinge 3 is connected to the other side of the optical fiber mounting frame 1, and the other end of the first hinge 3 is hinged to a first horizontal sleeve 6, the first horizontal sleeve 6 having an internal thread adapted to the first driving screw 4, and the first driving screw 4 being threadedly connected to the first horizontal sleeve 6; each group of light curtain mounting frames 2 is hinged to the first hinge 3 (via a bearing).

[0075] In this embodiment, the end of the first drive screw 4 is provided with a first rotating handle 7, and the first rotating handle 7 is provided with a plurality of circumferentially distributed through holes, the inner diameter of which is not less than the outer diameter of the first stop pin 5; the optical fiber mounting frame 1 is provided with a threaded hole adapted to the first stop pin 5, and the first stop pin 5 is passed through the through hole of the first rotating handle 7 and screwed into the threaded hole of the optical fiber mounting frame 1 to achieve the stopping effect.

[0076] When it is necessary to adjust the spacing of the light curtain mounting frames 2, turn the first rotating handle 7 to rotate the first drive screw 4, causing the first horizontal sleeve 6 to move horizontally relative to the first drive screw 4. This, in turn, moves the connecting rods of the first hinge 3, thereby moving each group of light curtain mounting frames 2 to adjust the distance between adjacent groups of light curtain mounting frames 2. After adjustment, pass the first stop pin 5 through the corresponding through hole of the first rotating handle 7 and screw it into the threaded hole of the fiber optic mounting frame 1 to achieve a stopping effect, thereby fixing the spacing of the light curtain mounting frames 2.

[0077] Example 4

[0078] This invention provides a laser velocimetry device for particle swarms. Its main structure is the same as that of embodiment 3, except that in this embodiment, the distance between adjacent optical fibers in the light curtain mounting frame 2 is adjustable.

[0079] Specifically, refer to Figures 1-11 In this embodiment, the optical fiber is movably mounted on the light curtain mounting frame 2; each of the four sides of the light curtain mounting frame 2 is equipped with a slide rail 2-1 (by screws), and a plurality of sliding supports 2-2 are slidably mounted on the slide rail 2-1. The sliding supports 2-2 are provided with mounting holes, and the optical fiber is inserted into the mounting holes and glued firmly, so as to realize the emission of laser in the light curtain mounting frame 2 and the capture of laser.

[0080] In this embodiment, the sliding support 2-2 slides along the slide rail 2-1 via a second driving device; the second driving device includes a second hinge 8, a second driving screw 9, a second stop pin 10, and two sets of fixed supports 11; the two sets of fixed supports 11 are respectively (by screws) fixed at both ends of the slide rail 2-1, the second driving screw 9 (by bearing) is rotatably mounted on one fixed support 11, one end of the second hinge 8 is connected to the other fixed support 11, and the other end of the second hinge 8 is hinged to a second horizontal sleeve 12, the second horizontal sleeve 12 is provided with an internal thread adapted to the second driving screw 9, and the second driving screw 9 is threadedly connected to the second horizontal sleeve 12; each set of sliding supports 2-2 is hinged to the second hinge 8 (by bearing).

[0081] In this embodiment, the end of the second drive screw 9 is provided with a second rotating handle 13. The second rotating handle 13 is provided with a plurality of circumferentially distributed through holes, the inner diameter of which is not less than the outer diameter of the second stop pin 10. The fixed support 11 is provided with a threaded hole that matches the second stop pin 10. By passing the second stop pin 10 through the through hole of the second rotating handle 13 and screwing it into the threaded hole of the fixed support 11, the stopping effect is achieved.

[0082] When it is necessary to adjust the fiber spacing, turn the second rotary handle 13 to rotate the second drive screw 9, causing the second horizontal sleeve 12 to move horizontally relative to the second drive screw 9. This, in turn, moves the connecting rods of the second hinge 8, thereby causing each set of sliding supports 2-2 to slide along the slide rail 2-1 to adjust the distance between adjacent sets of optical fibers. After adjustment, pass the second stop pin 10 through the corresponding through hole of the second rotary handle 13 and screw it into the threaded hole of the fixed support 11 to achieve a stopping effect, thus fixing the fiber spacing.

[0083] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A laser velocimetry method for particle swarms, characterized in that, Includes the following steps: S1. Set the speed measurement zone: ; S2. Activate the data acquisition device and particle emission device. The particle swarm emitted by the particle emission device passes through three light curtains. S3. Process the time-domain signals obtained from each channel of the data acquisition device one by one, and convert the acquired time-domain signals into an array of time points corresponding to the peak values ​​of the sensor trigger potentials, such as the time points located at the [missing information]. Daoguang screen The photoelectric sensor at that location was triggered. Then the recorded information is ; S4, the first light curtain and exist The moment is triggered, denoted as , and ; S5, captured by the second light curtain In the process, multiple locations where the second light curtain was triggered and their corresponding time points were found, forming a dataset. ,in ; S6, captured by the third light curtain In the process, multiple trigger locations and their corresponding time points are identified, forming a dataset. ,in ; S7, Calculate Dataset The modulus of the vector corresponding to each element in the vector Take the smallest modulus As a candidate, and its element is denoted as If in the dataset If an element can be found that satisfies equations (1) and (2), then the three data points are considered to correspond to the same particle, and the trigger position and time are recorded as follows: Otherwise, take the second smallest value in the second light curtain, and so on until a value that meets the above requirements is found. If no value that meets the requirements is found, it is considered that the particle has not been captured by the second or third light curtain, and the velocity measurement of the particle is abandoned. （1） （2） in, It is the acceleration due to gravity; air density; Particle density; The distance between the light curtains; S8. Repeat S5 to S7 for all trigger signals detected by the first light curtain, and match the signals detected by the second and third light curtains. S9. For the particles that were successfully matched in the previous step, calculate the velocity of each particle: 。 2. The laser velocimetry method for particle swarms according to claim 1, characterized in that, Laser beam center spacing Set as ,in, It is the diameter of the laser beam. It is the particle diameter The mean, It is the particle diameter The standard deviation.

3. The laser velocimetry method for particle swarms according to claim 1, characterized in that, Light curtain spacing .

4. A laser velocimetry device for implementing the laser velocimetry method according to any one of claims 1 to 3, characterized in that, Includes fiber optic mounting frame (1), multi-channel laser emitter, multi-channel laser receiver and particle emitter; The optical fiber mounting frame (1) is provided with several sets of parallel light curtain mounting frames (2), and optical fibers are installed on the light curtain mounting frames (2). The light beams generated by the optical fibers form a light curtain. The optical fiber includes an input optical fiber and an output optical fiber; one end of the input optical fiber is connected to a multi-channel laser emitting device, and the other end is installed on one side of the light curtain mounting frame (2); one end of the output optical fiber is connected to a multi-channel laser receiving device, and the other end is installed on the other side of the light curtain mounting frame (2); the positions of the input optical fiber and the output optical fiber correspond one-to-one. The particle emission device is located on one side of the optical fiber mounting frame (1), and its particle swarm emission direction is perpendicular to the light curtain.

5. The laser velocimetry device according to claim 4, characterized in that, The input optical fibers are arranged in several groups and installed in parallel on the left, right and upper and lower sides of the light curtain mounting frame (2); the number of output optical fibers is the same as the number of input optical fibers and is installed in parallel on the left, right and upper and lower sides of the light curtain mounting frame (2); the input optical fibers on the left, right and upper and lower sides are respectively connected to two groups of multi-channel laser emitting devices, and the output optical fibers on the left, right and upper and lower sides are respectively connected to two groups of multi-channel laser receiving devices.

6. The laser velocimetry device according to claim 4, characterized in that, The light curtain mounting frame (2) is slidably installed inside the fiber optic mounting frame (1) to adjust the distance between two adjacent light curtain mounting frames (2); The optical fiber mounting frame (1) is provided with an upper slide rail (1-1) and a lower slide rail (1-2). The upper and lower edges of the light curtain mounting frame (2) are respectively provided with an upper slider (1-3) and a lower slider (1-4) that are compatible with the upper slide rail (1-1) and the lower slide rail (1-2). The light curtain mounting frame (2) is slidably connected to the optical fiber mounting frame (1) through the slide rail and the slider.

7. The laser velocimetry device according to claim 6, characterized in that, The light curtain mounting frame (2) slides within the fiber optic mounting frame (1) via a first driving device; The first driving device includes a first hinge (3), a first driving screw (4), and a first stop pin (5); The first drive screw (4) is rotated and mounted on one side of the optical fiber mounting frame (1); one end of the first hinge (3) is connected to the other side of the optical fiber mounting frame (1), and the other end of the first hinge (3) is hinged to a first horizontal sleeve (6). The first horizontal sleeve (6) is provided with an internal thread that is compatible with the first drive screw (4), and the first drive screw (4) is threadedly connected to the first horizontal sleeve (6); each group of light curtain mounting frames (2) is hinged to the first hinge (3).

8. The laser velocimetry device according to claim 7, characterized in that, The first drive screw (4) is provided with a first rotating handle (7) at its end. The first rotating handle (7) is provided with a plurality of circumferentially distributed through holes. The inner diameter of the through holes is not less than the outer diameter of the first stop pin (5). The fiber optic mounting frame (1) is provided with a threaded hole that is compatible with the first stop pin (5). The first stop pin (5) is passed through the through hole of the first rotating handle (7) and screwed into the threaded hole of the fiber optic mounting frame (1) to achieve the stopping effect.

9. The laser velocimetry device according to claim 4, characterized in that, The optical fiber is movably mounted on the light curtain mounting frame (2); The light curtain mounting frame (2) is provided with slide rails (2-1) on all four sides. Several sliding supports (2-2) are slidably installed on the slide rails (2-1), and the optical fiber is installed on the sliding supports (2-2).

10. The laser velocimetry device according to claim 9, characterized in that, The sliding support (2-2) slides along the slide rail (2-1) via the second driving device; The second drive device includes a second hinge (8), a second drive screw (9), and two sets of fixed supports (11); The two sets of fixed supports (11) are respectively fixed at both ends of the slide rail (2-1). The second drive screw (9) is rotatably mounted on one fixed support (11). One end of the second hinge (8) is connected to the other fixed support (11). The other end of the second hinge (8) is hinged to a second horizontal sleeve (12). The second horizontal sleeve (12) is provided with an internal thread that is compatible with the second drive screw (9). The second drive screw (9) is threadedly connected to the second horizontal sleeve (12). Each set of sliding supports (2-2) is hinged to the second hinge (8).

Images