Dual-redundant linear laser for sar antenna deformation measurement and its alignment method

Abstract

The application relates to a double-redundancy linear laser for SAR antenna deformation measurement and a method for assembling and adjusting the same. The laser comprises two main and standby laser modules installed in a square shell. The laser module comprises a laser light source, a collimation assembly, a 90-degree conical mirror assembly and a circular mirror barrel. The application designs a standardized closed-loop assembly and adjustment process, sequentially completes single-module beam calibration, multi-distance rotating screening conical mirror, lathe unified processing mirror barrel installation reference and fixed interval double-module multi-point light line overlapping calibration, and discards the traditional manual grinding process, thereby avoiding dust pollution and greatly improving batch assembly consistency and assembly efficiency. Through the application, on-orbit redundancy reliability can be improved, optical element detection equipment procurement cost can be reduced, assembly and adjustment precision and efficiency can be improved, and the long-term use requirement of a satellite is met.

Description

Technical Field

[0001] This invention belongs to the field of assembly and adjustment technology of spaceborne SAR antenna deformation measurement equipment, specifically involving a dual-redundant single-line laser and its standardized closed-loop assembly and adjustment method, which is suitable for batch precision assembly of spaceborne and airborne high-precision optical measurement light sources. Background Technology

[0002] Spaceborne synthetic aperture radar (SAR) antennas are deployable, lightweight array structures. In orbit, they are susceptible to thermal deformation due to alternating hot and cold temperatures, leading to beam pointing errors and decreased imaging quality. Therefore, a linear laser, in conjunction with detection equipment, is required to measure this deformation in orbit, ensuring the performance of the SAR system.

[0003] Existing linear laser equipment of the same type has several engineering defects: 1. Conventional solutions use a single laser module without redundancy. If a failure occurs in orbit, the entire measurement system will fail. Satellites generally have a lifespan of more than 5 years. The single laser module without redundancy design cannot meet the requirements of long lifespan and high reliability of satellites. Some dual-laser solutions do not use an integrated base, resulting in poor structural rigidity, and it is difficult to achieve consistent overlap between the main and backup beams at near and far distances.

[0004] 2. The conical reflector in the laser module is required to have an angle of 90°. However, the traditional method relies on an angle measuring instrument to determine whether the angle of the conical reflector is 90°. Angle measuring instruments such as interferometers and angle rulers are either expensive and complicated to operate, or have poor measurement accuracy, which increases the cost and difficulty of installation and adjustment. Moreover, the detection scenario is out of touch with the actual use scenario, and the judgment result is prone to deviation.

[0005] 3. Traditionally, the overlap of two linear laser beams at a specific height requires manual grinding of the module's bottom surface. This method has three major drawbacks: First, it causes severe dust pollution, with dust easily adhering to the surface of optical components and affecting beam quality. Second, it is extremely inefficient, requiring 2-3 days to assemble and adjust a single module, making it difficult to meet the needs of mass production. Third, it suffers from poor precision consistency, with large errors in manual operation. The assembly and adjustment precision deviation between different operators and different batches of products can reach 2-3 mm, which cannot meet the requirements of high-precision spaceborne measurement.

[0006] 4. Existing publicly available literature on linear lasers only discloses the static optical path structure of the product, without disclosing a complete set of standardized mass production assembly and adjustment processes. This fails to address the pain points of poor mass production consistency and long debugging cycles. Summary of the Invention To address the aforementioned technical issues, this invention provides a dual-redundant single-line laser for SAR antenna deformation measurement and its assembly and adjustment method, which improves on-orbit reliability, reduces the cost and threshold of detection, enhances the accuracy and efficiency of assembly and adjustment, and meets the requirements for use in spaceborne environments.

[0007] The technical objective of this invention is achieved through the following technical solution: A method for assembling and adjusting a dual-redundant single-line laser for measuring deformation of a spaceborne SAR antenna. The dual-redundant single-line laser includes two laser modules, one primary and one backup. The two laser modules are installed in square housings, with the primary laser module located directly in front of the backup laser module. Each laser module includes a laser source, a collimation assembly, a 90° conical reflector assembly, and a circular tube. The laser source is installed at the beam incident end of the collimation assembly, and the 90° conical reflector assembly is installed at the beam exit end of the collimation assembly. The method includes: S1. Assemble the laser source and collimation component into one unit, and adjust the axial distance between the aspherical lens of the collimation component and the spot analyzer until the divergence angle of the spot formed by the emitted beam is ≤0.1mrad and the spot shape is uniform and without distortion. Then the beam collimation adjustment is completed. S2. Install the 90° conical reflector assembly at the beam output end of the collimation assembly to form a laser assembly. Under three working conditions at a distance of at least 1m, 3m and 5m from the laser assembly, measure the height change of the emitted light from the 90° conical reflector assembly at different distances, and screen the 90° conical reflector assemblies whose light height change meets the requirements. S3. Install the laser component into the circular lens barrel to form a laser module. Clamp the laser module laterally on the chuck of a high-precision lathe. Using the coaxiality of the far-field light as a reference, turn the bottom surface of the module in the circular lens barrel through the lathe. The distance from the bottom surface of the module after turning to the center of the light is equal to the output height of the laser module. S4. Install the laser modules that have been machined into the square housing according to the requirement of a front-to-back spacing of 30mm ± 0.1mm. Adjust the posture of the two laser modules and check the overlap of the light beams of the two laser modules at different distances and angles. Fine-tune the posture of the laser modules according to the overlap of the light beams until the overlap deviation is ≤ 1mm.

[0008] Furthermore, when performing beam collimation adjustment, the following steps are included: S11. Fix the collimation assembly on a horizontal worktable, install the laser source at the beam incident end of the collimation assembly, and set a collimator at the beam exit end of the collimation assembly 500mm away from the collimation assembly; set a spot analyzer at the beam exit position of the collimator. S12. Turn on the laser light source and measure the light spot at the focal position of the collimator using a spot analyzer; S13. Adjust the axial spacing between the laser source and the aspherical lens of the collimation component until the beam divergence angle displayed by the beam analyzer is ≤0.1mrad and the beam shape is uniform and without distortion. Then lock the axial spacing between the laser source and the aspherical lens.

[0009] Furthermore, the screening of 90° conical mirror assemblies includes the following steps: S21. After completing the beam collimation adjustment of the collimation component, install the 90° conical reflector component at the beam output end of the collimation component to form a laser component, and fix the whole assembly on the adjustment frame with 360° rotation function. S22. Turn on the laser source and rotate the adjustment frame to make the light emission direction of the 90° conical reflector assembly horizontal; S23. Set up a spot analyzer 5m away from the light emission direction of the 90° conical reflector assembly. Adjust the spot analyzer so that the light emitted from the 90° conical reflector assembly is centered on the target surface image of the spot analyzer. Record the center height of the laser light in the target surface image. S24. Set up a spot analyzer 3m away from the light emission direction of the 90° conical mirror assembly. Adjust the spot analyzer so that the light emitted from the 90° conical mirror assembly is completely imaged on the target surface of the spot analyzer. Record the center height of the laser light image on the target surface. S25. Set up a spot analyzer 1m away from the light emission direction of the 90° conical mirror assembly, adjust the spot analyzer so that the light emitted from the 90° conical mirror assembly is completely imaged on the target surface of the spot analyzer, and record the center height of the laser light image on the target surface. S26. If the height variation of the laser beam image on the target surface measured by the spot analyzer at 5m, 3m and 1m is kept ≤0.1mm, then the accuracy of the 90° conical reflector assembly meets the requirements.

[0010] Furthermore, the following steps are included when performing the reference turning of the bottom of the circular lens barrel: S31. Install the laser component into the circular lens tube to form a laser module. Clamp the laser module horizontally on the chuck of a high-precision lathe. Adjust the angle of the chuck so that the light emission direction of the laser module is perpendicular to the horizontal plane. S32. Set up a spot analyzer 5m away from the laser module's light output direction, and adjust the height and angle of the spot analyzer so that the vertical light emitted by the laser module is centered on the target surface. S33. Start the lathe so that the laser module rotates synchronously with the lathe chuck. Observe the left and right displacement of the laser beam on the spot analyzer. If the beam shifts left and right, fine-tune the clamping angle of the chuck so that the left and right displacement of the laser beam during rotation is kept ≤0.05mm. Then lock the clamping angle. S34. Using the left and right centers of the laser beam as the starting point for tool setting, move the cutting tool according to the theoretical output height value of the laser module to machine the bottom surface of the circular lens barrel module.

[0011] Furthermore, the following steps are included when adjusting the beam alignment of the two laser modules: S41. Install the laser modules that have been machined into the square housing according to the requirement of a front-to-back spacing of 30mm ± 0.1mm, and adjust the posture of the two laser modules to make the light output direction consistent. S42. Turn on the laser source. Fix the spot analyzer at 1m, 3m and 5m in the direction of laser beam output from the laser module. Adjust the height and angle of each spot analyzer so that the laser beams from both laser modules can be imaged at the center of the target surface of the spot analyzer. S43. Observe the overlap of the laser beams of the two laser modules on the spot analyzer at six angle positions in the plane at a position of 5m. If there is a deviation, fine-tune the attitude of the laser modules until the laser beams of the two laser modules overlap in the center of the target surface, and the overlap deviation is ≤1mm; S44. Observe the overlap of laser beams from the two laser modules on the spot analyzer at six angular positions within a plane at a 3m location; S45. Observe the overlap of the laser beams of the two laser modules on the spot analyzer at six angle positions in the plane at a position of 1m. S46. If the overlap deviation of the laser beams of the two laser modules measured by the spot analyzer at 6 angular positions at three distances is ≤1mm, then the attitude of the two laser modules is locked.

[0012] Furthermore, the method also includes, during step S23, recording the center height of the laser beam image on the target surface and then rotating the adjustment frame to observe the height change of the laser beam image on the target surface of the spot analyzer. If the height change is >0.1mm, the pitch and yaw angles of the adjustment frame are adjusted to correct the attitude of the laser component so that the height change is ≤0.1mm. The adjustment frame is then rotated until the height change of the laser beam image on the target surface of the spot analyzer is always ≤0.1mm.

[0013] This invention also provides a dual-redundant single-line laser for measuring the deformation of a spaceborne SAR antenna. The dual-redundant single-line laser includes two laser modules, one primary and one backup. The two laser modules are respectively installed in a square housing, with the primary laser module located directly in front of the backup laser module. The two laser modules are offset by 30±0.1mm. Each laser module is assembled from a laser source, a collimation component, a 90° conical reflector component, and a circular lens tube. The two laser modules are machined on a lathe to create a reference bottom surface. The overlap accuracy of the light rays from the two laser modules is ≤1mm at at least 1m, 3m, and 5m.

[0014] Furthermore, the laser source is a 660nm semiconductor laser diode, and the collimation assembly is equipped with an aspherical lens for collimating the diverging beam output from the semiconductor laser diode along the fast and slow axes.

[0015] Furthermore, the laser source, collimation component, and 90° conical reflector component are assembled to form a laser component. The outer wall of the laser component is provided with a positioning boss, and the inner wall of the circular lens tube is provided with an annular mounting groove corresponding to the positioning boss. During installation, the positioning boss is engaged into the annular mounting groove.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. With the assembly and adjustment method of the dual-redundant single-line laser for spaceborne SAR antenna deformation measurement of the present invention, the angle detection of the 90° conical reflector assembly no longer relies on expensive precision instruments, effectively reducing costs and operational complexity, while ensuring measurement accuracy. The detection cost can be reduced by more than 80%, the efficiency can be increased by 50%, and the detection results are consistent with the actual use scenario.

[0017] 2. The assembly and adjustment method of the dual-redundant single-line laser for spaceborne SAR antenna deformation measurement of the present invention uses a lathe to turn the bottom surface of the circular lens module. Compared with manual grinding, it has the advantages of high efficiency, less contamination of optical components, and high consistency. The assembly and adjustment deviation is reduced from 2-3mm to ≤0.1mm, and the beam quality qualification rate is increased from 75% to 99%, which can meet the requirements of clean assembly and mass production of aerospace products.

[0018] 3. The assembly and adjustment method of the dual redundant single-line laser for spaceborne SAR antenna deformation measurement proposed in this invention can achieve stable overlap of two single-line lasers at different distances, with standardized and detailed parameter control, ensuring assembly and adjustment accuracy and consistency.

[0019] 4. By using the assembly and adjustment method of the dual-redundant single-line laser for spaceborne SAR antenna deformation measurement of the present invention, the assembly and adjustment time of a single laser module is shortened from 2-3 days to 2-3 hours, and the efficiency is improved by more than 10 times.

[0020] 5. The dual-redundant single-line laser for spaceborne SAR antenna deformation measurement of the present invention increases on-orbit reliability by setting up two laser modules, one as the main laser module and the other as a backup laser module. If a single laser module fails, the backup laser module can be started immediately, meeting the long-term working requirement of spaceborne operation of ≥5 years. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the optical path during beam collimation adjustment in this invention.

[0022] Figure 2This is a schematic diagram of the screening optical path of the 90° conical reflector assembly in this invention.

[0023] Figure 3 This is a schematic diagram of the laser module installation during the bottom reference turning of the circular mirror tube in this invention.

[0024] Figure 4 This is a schematic diagram of the laser beam overlap adjustment of two laser modules in this invention.

[0025] Figure 5 This is a schematic diagram of the laser beam horizontally hitting the spot analyzer in this invention.

[0026] Figure 6 This is a schematic diagram of the laser beam hitting the spot analyzer perpendicularly in this invention.

[0027] Figure 7 This is a schematic diagram of the laser module in this invention.

[0028] In the picture: 1. Laser source; 2. Collimation assembly; 3. 90° conical mirror assembly; 4. Circular lens tube; 5. Collimator; 6. Spot analyzer; 7. Adjustment frame; 8. Lathe; 9. Square housing; 10. Main laser module; 11. Backup laser module; 2-1. Aspherical lens; 3-1. Positioning boss; 3-2. Laser beam; 4-1. Annular mounting groove; 8-1. Chuck; 8-2. Lathe tool. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to specific embodiments: A dual-redundant single-line laser for measuring deformation of spaceborne SAR antennas comprises two laser modules, one primary and one backup. The two laser modules are respectively installed within a square housing 9. The primary laser module 10 is located directly in front of the backup laser module 11, with a staggered distance of 30±0.1mm between the two modules. The two laser modules operate independently without interference. Each laser module includes a laser source 1, a collimation assembly 2, a 90° conical reflector assembly 3, and a circular mirror tube 4, as shown below. Figure 7As shown, laser source 1 is installed at the beam incident end of collimation component 2, and 90° conical reflector component 3 is installed at the beam exit end of collimation component 2. Laser source 1, collimation component 2, and 90° conical reflector component 3 are assembled to form a laser assembly. This laser assembly is then installed inside a circular mirror tube 4 to form a laser module. Each laser module is equipped with an independent light exit window (quartz material, transmittance ≥98%) to avoid mutual obstruction and light field interference. The two laser modules are machined on a lathe to ensure that the overlap accuracy of the linear laser beams of the two laser modules is ≤1mm at at least 1m, 3m, and 5m.

[0030] To address the issues of the relative positions of the 90° conical mirror assembly 3 and the collimation assembly 2 being easily affected by vibration and the poor consistency of repeated assembly and adjustment in traditional split structures, the collimation assembly 2 and the 90° conical mirror assembly 3 are assembled into a laser assembly through a precision mechanical interface.

[0031] More specifically, the laser source 1 is a 660nm semiconductor laser diode, and the collimation component 2 is provided with an aspherical lens 2-1 for collimating the diverging beam output by the semiconductor laser diode along the fast and slow axes.

[0032] Preferably, the outer wall of the laser assembly is provided with a positioning boss 3-1, specifically located on the 90° conical reflector assembly 3. The inner wall of the circular mirror tube 4 is provided with an annular mounting groove 4-1 corresponding to the positioning boss. During installation, the positioning boss 3-1 is engaged into the annular mounting groove 4-1. Figure 7 As shown. During assembly, the laser assembly is pushed in along the axial direction of the circular lens barrel 4. When the positioning boss slides into the mounting groove, the operator can feel a clear locking sensation, ensuring that the laser assembly reaches the preset axial position. Preferably, the mating gap between the annular mounting groove 4-1 and the positioning boss 3-1 is controlled within 0.02mm, which can achieve a repeatability positioning accuracy of ±0.01mm radially and ±0.01mm axially.

[0033] Preferably, in one implementation process, the square housing 9 and the high-precision base adopt an integrated structure. The base is located inside the square housing 9 and is integrally formed by Invar steel, with dimensions of 150mm×100mm×80mm and a base levelness ≤0.01mm / m. The main laser module 10 and the backup laser module 11 are respectively fixed to the base inside the square housing 9 with three M3 screws. The screws are evenly distributed to ensure a firm fixation and uniform force distribution, avoiding attitude displacement of the laser modules during tightening. The square housing 9 is directly connected and fixed to the satellite platform with three M5 screws, adapting to the spaceborne installation requirements and improving the overall structure's vibration resistance. After mechanical vibration tests and thermal vacuum tests, the pointing variation is less than 25μrad, meeting the requirements for use in high and low temperature and vibration environments on-orbit, thereby achieving high-precision alignment of the main and backup laser modules in the near and far fields and reliable redundant operation on-orbit, meeting the deformation measurement requirements of the spaceborne SAR antenna.

[0034] The diverging beam output from a 660nm semiconductor laser diode can be approximated as a Gaussian beam. After passing through an aspherical lens with focal length f, the far-field divergence angle is... With waist radius The relationship follows: In the formula, With a laser wavelength of 660nm, during assembly and adjustment, the axial distance d between the 660nm semiconductor laser diode and the aspherical lens is adjusted to approach the focal length f, thereby minimizing the divergence angle of the output beam. When d=f, the system reaches the theoretically optimal collimation state. This is achieved through beam collimation adjustment. Fast and slow axis collimation is performed to eliminate beam divergence and form a parallel beam. The divergent beam output by the 660nm semiconductor laser diode is collimated by an aspherical lens to eliminate beam divergence and form a parallel beam. The measured spot diameter of the parallel beam at 4.5m is 4.28mm.

[0035] A parallel beam of light is incident on a 90° conical reflector assembly, and after reflection, forms an approximately 360° fan-shaped linear light curtain. After being placed in a circular lens tube and the structural obstruction is removed, a 190° fan-shaped linear light curtain remains, with a measured beam width of 2.15 mm. Because the main laser module 10 and the backup laser module 11 are arranged front and back, the main laser module 10 will block approximately 30° of the light field at the center of the backup laser module 11. Therefore, the effective overlap area of ​​the two laser beams is two 80° fan-shaped areas, achieving 360° full coverage without affecting the measurement.

[0036] The primary laser module physically obstructs the backup laser module; the calculation of the effective overlapping sector area is based on a geometric obstruction model. Where W is the module width and L is the distance between the main laser module and the backup laser module (30mm), this explains why two effective overlapping fan-shaped areas of 80° are ultimately formed.

[0037] To achieve the assembly and adjustment of the dual-redundant single-line laser for spaceborne SAR antenna deformation measurement as described above, this embodiment also provides a method for assembling and adjusting the dual-redundant single-line laser for spaceborne SAR antenna deformation measurement, the method comprising: S1. Assemble the laser source 1 and the collimation component 2 into one unit, and adjust the axial distance between the aspherical lens 2-1 of the collimation component 2 and the laser source 1 until the divergence angle of the emitted beam is ≤0.1mrad and the beam shape is uniform and without distortion. Then the beam collimation adjustment is completed. S2. Install the 90° conical reflector assembly 3 at the beam exit end of the collimating assembly 2 to form a laser assembly. Place the beam analyzer 6 5m away from the laser assembly and adjust the beam analyzer 6 so that the position of the light on the beam analyzer 6 is as follows: Figure 5 As shown, the laser assembly is rotated in the horizontal plane. The laser assembly is adjusted based on the height change of the light beam on the beam analyzer 6 until the height change of one rotation is greater than 0.1mm. This indicates that the beam is horizontal to the ground, and the height is recorded. The beam analyzer 6 is placed at 5m, 3m, and 1m of the assembly, and the light height is recorded. This allows for the selection of the 90° conical reflector assembly 3 based on the magnitude of the height change of the emitted light beam at these three locations. The relationship between the constant height of light rays at different positions and the accuracy of the 90° conical mirror assembly is positively correlated: if the apex angle deviation of the 90° conical mirror assembly is... The height of the light spot fluctuates at a distance R. It can be represented as: When the required height deviation is at R=5m ≤0.1mm, by reverse deduction, it can be seen that this screening method can ensure that the apex angle machining accuracy of the 90° conical reflector assembly is better than: The above formula shows that the fluctuation of light height is linearly related to the angular error of the 90° conical reflector assembly. Therefore, high-precision screening of the 90° conical reflector assembly can be indirectly achieved through far-field height deviation.

[0038] S3. The laser module is installed into the circular lens barrel 4 to form a laser module. The laser module is horizontally clamped on the chuck 8-1 of the high-precision lathe 8. The bottom surface of the module of the circular lens barrel 4 is machined by the lathe 8. Let the axis of rotation of the spindle of lathe 8 be the z-axis, the vertical direction be the y-axis, and the horizontal direction be the x-axis, as follows: Figure 3As shown, ideally, the optical axis of the laser module is perfectly aligned with the rotation axis of the lathe. In this state, the bottom surface of the module cut by the cutting tool along the z-axis is perfectly parallel to the optical axis. However, in reality, due to clamping errors, the optical axis has a slight tilt relative to the rotation axis. ; When the laser module rotates with the main shaft, if the optical axis does not coincide with the rotation axis, the spot will be observed to jump as it rotates on the spot analyzer in the far field (at a distance R). During rotation, the maximum fluctuation deviation of the light spot in the horizontal direction (y-axis) is: y (horizontal offset), the maximum fluctuation deviation of the light spot in the vertical direction (z-axis) is z (vertical offset). Under a small-angle approximation, the resultant pointing deviation angle of the optical axis in space. It can be obtained by combining the angular deviations of two orthogonal directions: In the formula, R is the distance from the laser module to the spot analyzer (5m, 3m, 1m). In machining, parallelism error is usually defined as the distance within a given length. The maximum deviation of the actual surface from the reference plane. This represents the effective contact length of the bottom surface of the laser module or the length of the mounting base.

[0039] Because parallelism error is actually the cumulative effect of angular deviation over the length of the base surface, therefore: Will Substituting into the above equation, we get: To directly express the positional deviation ratio per unit length (i.e., slope error), the slope is omitted. Directly expressed as: This formula demonstrates the superiority of using lathe turning instead of manual grinding: High-sensitivity detection: Detection at a distance of 5m y and Even minute variations in z (with an error controlled within ≤0.05mm) can lead to the extremely precise parallelism error. .

[0040] Precision quantification: The formula reveals that as long as the runout during the rotation process is minimized, the bottom surface of the machined part can achieve the ≤0.1mm level of assembly and adjustment consistency required by the spaceborne SAR antenna, which is far superior to the 2-3mm of traditional hand grinding.

[0041] S4. Install the laser modules that have been machined into the square housing 9 according to the requirement of a front-to-back spacing of 30mm ± 0.1mm. Adjust the posture of the two laser modules to make the light output direction consistent. Measure the overlap of the light from the two laser modules at different distances and angles and adjust accordingly. Adjust the posture of the laser modules according to the overlap deviation until the overlap deviation is ≤ 1mm.

[0042] More specifically, during beam collimation adjustment in step S1, the following steps are included: S11. Fix the collimation assembly 2 on a horizontal worktable. Install the laser source 1 at the beam incident end of the collimation assembly 2. Place a collimator 5 500mm away from the collimation assembly at the beam exit end of the collimation assembly 2, with the laser beam exit direction aligned with the entrance of the collimator 5. Place a beam analyzer 6 at the exit position of the collimator 5, and adjust the height and angle of the beam analyzer 6 so that the beam emitted from the collimator 5 can be completely imaged at the center of the target surface of the beam analyzer 6. Figure 1 As shown; S12. Turn on laser source 1 and adjust the laser output power to the design value (1-3mW). Measure the spot at the focal position of the collimator using a spot analyzer. Observe the spot shape and divergence angle data on the spot analyzer 6. In the initial state, the spot may be divergent with a large divergence angle. S13. Adjust the axial distance between the laser source 1 and the aspherical lens 2-1 of the collimating assembly 2. The adjustment range is 0-10mm, and the adjustment accuracy is 0.01mm. Record the divergence angle data of the light spot after each adjustment until the divergence angle of the light spot displayed by the light spot analyzer 6 is ≤0.1mrad and the light spot shape is uniform and without distortion. Then lock the axial distance between the laser source 1 and the aspherical lens 2-1 and fix it with a pressure ring to complete the beam collimation adjustment of the collimating assembly 2. According to actual measurement, the diameter of the light spot at 4.5m after being shaped by the aspherical lens 2-1 is 4.28mm.

[0043] The main laser module 10 and the backup laser module 11 are adjusted for beam collimation using the methods described above. After adjustment, the collimation accuracy of the two laser modules can be kept consistent.

[0044] More specifically, the screening of the 90° conical mirror assembly in step S2 includes the following steps: S21. After completing the beam collimation adjustment of the collimation component 2, the 90° conical mirror component 3 is installed at the beam output end of the collimation component 2 to form a laser component, and the whole assembly is fixed on the adjustment frame 7 with 360° rotation function. The adjustment frame is a six-dimensional adjustment frame with 360° rotation function. S22. Turn on the laser source 1 and rotate the angle of the adjustment frame 7 so that the light emission direction of the 90° conical reflector assembly 3 is horizontal. S23. A light spot analyzer 6 is installed 5m away from the light emission direction of the 90° conical reflector assembly 3, such as... Figure 2 As shown, the light spot analyzer is adjusted so that the light emitted from the 90° conical reflector assembly 3 is positioned at the upper and lower center of the target surface of the light spot analyzer 6, as shown. Figure 5 As shown, ensure that the laser emission direction is perpendicular to the target surface of the spot analyzer 6, and record the center height of the laser beam (line laser) image on the target surface; preferably, rotate the angle of the adjustment frame 7, and observe the height change of the laser beam image on the target surface of the spot analyzer 6 during the rotation. If the height change is >0.1mm, adjust the pitch and yaw angles of the adjustment frame 7 to correct the attitude of the laser assembly so that the height change is ≤0.1mm; continue to rotate the adjustment frame 7 until the height change of the laser beam image on the target surface of the spot analyzer 6 is always ≤0.1mm, indicating that the laser beam is parallel to the ground at this time.

[0045] S24. Set up a spot analyzer 6 at 3m in the light emission direction of the 90° conical reflector assembly 3 to record the upper and lower center heights of the laser beam imaging on the target surface. S25. Set up a spot analyzer 6 1m away from the light emission direction of the 90° conical reflector assembly 3 to record the center height of the laser beam imaging on the target surface. S26. If the height change of the laser beam image on the target surface measured by the spot analyzer 6 at 5m, 3m and 1m is kept within ≤0.1mm, then the accuracy of the 90° conical reflector assembly 3 meets the requirements; if the height change at any distance is not kept within 0.1mm, then a new 90° conical reflector assembly 3 needs to be replaced and steps S21-S26 need to be repeated for screening.

[0046] The above process is used to screen the 90° conical reflector assembly 3 of the main laser module 10 and the backup laser module 11 to ensure that the accuracy of the 90° conical reflector assembly 3 of the two laser modules is consistent, laying the foundation for the subsequent overlap of the light from the main and backup laser modules.

[0047] More specifically, during the reference turning of the bottom of the circular lens barrel in step S3, the following steps are included: S31. Install the laser assembly into the circular lens tube 4 to form a laser module. Clamp the laser module horizontally on the chuck 8-1 of the high-precision lathe. Adjust the angle of the chuck 8-1 so that the light emission direction of the laser module is perpendicular to the horizontal plane. S32. A beam analyzer 6 is installed 5m away from the laser module's output direction, such as... Figure 3 As shown, adjust the height and angle of the spot analyzer 6 so that the laser module is centered on the target surface of the spot analyzer 6, as shown. Figure 6 As shown; S33. Start the lathe 8 and rotate the spindle of the lathe 8 at a speed of 1r / min so that the laser module rotates synchronously with the chuck 8-1 of the lathe 8. Observe the left and right changes of the laser beam on the spot analyzer 6. If there is a left and right deviation, fine adjust the clamping angle of the chuck 8-1 so that the left and right deviation of the laser beam is kept ≤0.05mm during the rotation. Then lock the clamping angle. S34. Using the left and right centers of the laser beam as the starting point for tool setting, and the output height of the laser module as the stroke, while the chuck 8-1 rotates, the cutting tool 8-2 moves to machine the bottom surface of the circular lens barrel 4. The designed output height of the laser module is 48mm. Moving the cutting tool 48mm, the bottom surface of the circular lens barrel 4 is machined using the cutting tool 8-2. This ensures that the bottom surface of the circular lens barrel 4 remains parallel to the linear laser beam, and also ensures that the output height reaches the designed specified height (error ≤ 0.05mm). The bottom reference machining of the circular lens barrel 4 of the main laser module 10 and the backup laser module 11 is completed using the above method.

[0048] More specifically, during step S4, when adjusting the beam alignment of the two laser modules, such as Figure 4 As shown, it includes the following steps: S41. Install the laser modules that have been machined into the square housing according to the requirement of a front-to-back spacing of 30mm ± 0.1mm. The main laser module 10 is located in front of the spare laser module 11. Adjust the posture of the two laser modules so that the light output direction is consistent. S42. Turn on the laser source 1. Fix the spot analyzer 6 at 1m, 3m and 5m in the laser module's output direction respectively. Adjust the height and angle of each spot analyzer 6 so that the laser beams of the two laser modules can be imaged at the center of the target surface of the spot analyzer 6. S43. Observe the overlap of the laser beams of the two laser modules on the spot analyzer 6 at six angle positions in the plane at a position of 5m. In this embodiment, at a position 5m away from the light output position, three angles are evenly selected in the effective overlap area of ​​the two 80° fan-shaped regions of the two laser modules. Measurements are taken at the 0°, 40° and 80° positions of the 80° fan-shaped regions. If there is a deviation, the attitude of the laser modules is finely adjusted until the laser beams of the two laser modules are imaged and overlapped at the center of the target surface, with an overlap deviation ≤1mm. S44. Observe the overlap of the laser beams of the two laser modules on the spot analyzer 6 at 6 angle positions in the plane at a position of 3m. The angle selection is the same as in step S43. S45. Observe the overlap of the laser beams of the two laser modules on the spot analyzer 6 at 6 angle positions in the plane at a position of 1m. The angle selection is the same as in step S43. S46. If the overlap deviation of the laser beams of the two laser modules measured by the spot analyzer at 6 angular positions at three distances is ≤1mm, then the attitude of the two laser modules is locked.

[0049] It should be noted that the main difference between the laser beam and the laser ray described in this application lies in the shape of the image. The laser beam emitted from the collimating component of the laser source is imaged as a light spot, while the image after being emitted from the 90° conical reflector component is an image of a line. Therefore, before passing through the 90° conical reflector component, it is a laser beam, and after passing through the 90° conical reflector component, it is a laser ray.

[0050] This embodiment is merely a further explanation of the present invention and is not intended to limit the present invention. Those skilled in the art can make non-inventive modifications to this embodiment as needed after reading this specification, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for assembling and adjusting a dual-redundant single-line laser for measuring the deformation of a spaceborne SAR antenna, characterized in that, A dual-redundant linear laser includes two laser modules, one primary and one backup. The two laser modules are respectively installed within a square housing, with the primary laser module located directly in front of the backup laser module. Each laser module includes a laser source, a collimation assembly, a 90° conical mirror assembly, and a circular lens tube. The laser source is installed at the beam incident end of the collimation assembly, and the 90° conical mirror assembly is installed at the beam exit end of the collimation assembly. The method includes: S1. Assemble the laser source and collimation component into one unit, and adjust the axial distance between the aspherical lens of the collimation component and the laser source until the divergence angle of the emitted beam is ≤0.1mrad and the beam shape is uniform and without distortion. Then the beam collimation adjustment is completed. S2. Install the 90° conical reflector assembly at the beam output end of the collimation assembly to form a laser assembly. Under three working conditions at a distance of at least 1m, 3m and 5m from the laser assembly, measure the height change of the emitted light from the 90° conical reflector assembly at different distances, and screen the 90° conical reflector assemblies whose light height change meets the requirements. S3. Install the laser component into the circular lens barrel to form a laser module. Clamp the laser module laterally on the chuck of a high-precision lathe. Using the coaxiality of the far-field light as a reference, turn the bottom surface of the module in the circular lens barrel through the lathe. The distance from the bottom surface of the module after turning to the center of the light is equal to the light output height of the laser module. S4. Install the laser modules that have been machined into the square housing according to the requirement of a front-to-back spacing of 30mm ± 0.1mm. Adjust the posture of the two laser modules and measure the overlap of the light rays of the two laser modules at different distances and angles. Fine-tune the posture of the laser modules according to the overlap of the light rays until the overlap deviation is ≤ 1mm.

2. The assembly and adjustment method of a dual-redundant single-line laser for measuring the deformation of a spaceborne SAR antenna according to claim 1, characterized in that, When performing beam collimation adjustment, the following are included: S11. Fix the collimation assembly on a horizontal worktable, install the laser source at the beam incident end of the collimation assembly, and set a collimator at the beam exit end of the collimation assembly 500mm away from the collimation assembly; set a spot analyzer at the beam exit position of the collimator. S12. Turn on the laser light source and measure the light spot at the focal position of the collimator using a spot analyzer; S13. Adjust the axial spacing between the laser source and the aspherical lens of the collimation component until the beam divergence angle displayed by the beam analyzer is ≤0.1mrad and the beam shape is uniform and without distortion. Then lock the axial spacing between the laser source and the aspherical lens.

3. The assembly and adjustment method of a dual-redundant single-line laser for spaceborne SAR antenna deformation measurement according to claim 1, characterized in that, The screening process for 90° conical mirror assemblies includes the following steps: S21. After completing the beam collimation adjustment of the collimation component, install the 90° conical reflector component at the beam output end of the collimation component to form a laser component, and fix the whole assembly on the adjustment frame with 360° rotation function. S22. Turn on the laser source and rotate the adjustment frame to make the light emission direction of the 90° conical reflector assembly horizontal; S23. Set up a spot analyzer 5m away from the light emission direction of the 90° conical mirror assembly, adjust the spot analyzer so that the light emitted from the 90° conical mirror assembly is imaged on the target surface of the spot analyzer, and record the center height of the laser light image on the target surface. S24. Set up a spot analyzer 3m away from the light emission direction of the 90° conical mirror assembly. Adjust the spot analyzer so that the light emitted from the 90° conical mirror assembly is imaged on the target surface of the spot analyzer. Record the center height of the laser light image on the target surface. S25. Set up a spot analyzer 1m away from the light emission direction of the 90° conical mirror assembly, adjust the spot analyzer so that the light emitted from the 90° conical mirror assembly is completely imaged on the target surface of the spot analyzer, and record the center height of the laser light image on the target surface. S26. If the height variation of the laser beam image on the target surface measured by the spot analyzer at 5m, 3m and 1m is kept ≤0.1mm, then the accuracy of the 90° conical reflector assembly meets the requirements.

4. The assembly and adjustment method of a dual-redundant single-line laser for measuring the deformation of a spaceborne SAR antenna according to claim 1, characterized in that, When performing reference turning on the bottom of a circular lens barrel, the following steps are included: S31. Install the laser component into the circular lens tube to form a laser module. Clamp the laser module horizontally on the chuck of a high-precision lathe. Adjust the angle of the chuck so that the light emission direction of the laser module is perpendicular to the horizontal plane. S32. Set up a spot analyzer 5m away from the laser module's output direction, and adjust the height and angle of the spot analyzer so that the light emitted by the laser module is centered on the target surface of the spot analyzer. S33. Start the lathe so that the laser module rotates synchronously with the lathe chuck. Observe the change in the left and right position of the laser beam on the spot analyzer. If the left and right position changes, fine-tune the clamping angle of the chuck so that the change in the left and right position of the laser beam during the rotation is kept ≤0.05mm. Then lock the clamping angle. S34. Using the left and right centers of the laser beam as the starting point for tool setting, move the cutting tool according to the theoretical light output height value of the module to machine the bottom surface of the circular lens barrel.

5. The assembly and adjustment method of a dual-redundant single-line laser for measuring the deformation of a spaceborne SAR antenna according to claim 1, characterized in that, When performing beam alignment adjustment between two laser modules, the following steps are included: S41. Install the laser modules that have been machined into the square housing according to the requirement of a front-to-back spacing of 30mm ± 0.1mm, and adjust the posture of the two laser modules to make the light output direction consistent. S42. Turn on the laser source. Fix the spot analyzer at 1m, 3m and 5m in the direction of laser beam output from the laser module. Adjust the height and angle of each spot analyzer so that the laser beams from both laser modules can be imaged at the center of the target surface of the spot analyzer. S43. Observe the overlap of the laser beams of the two laser modules on the spot analyzer at six angle positions in the plane at a position of 5m. If there is a deviation, fine-tune the attitude of the laser modules until the laser beams of the two laser modules overlap in the center of the target surface, and the overlap deviation is ≤1mm; S44. Observe the overlap of the laser beams of the two laser modules on the spot analyzer at six angle positions in the plane at a position of 3m. S45. Observe the overlap of the laser beams of the two laser modules on the spot analyzer at six angle positions in the plane at a position of 1m. S46. If the overlap deviation of the laser beams of the two laser modules measured by the spot analyzer at 6 angular positions at three distances is ≤1mm, then the attitude of the two laser modules is locked.

6. The assembly and adjustment method of a dual-redundant single-line laser for spaceborne SAR antenna deformation measurement according to claim 3, characterized in that, The method further includes, in step S23, recording the center height of the laser beam image on the target surface and then rotating the adjustment frame to observe the height change of the laser beam image on the target surface of the spot analyzer. If the height change is >0.1mm, the pitch and yaw angles of the adjustment frame are adjusted to correct the attitude of the laser component so that the height change is ≤0.1mm. The adjustment frame is then rotated until the height change of the laser beam image on the target surface of the spot analyzer is always ≤0.1mm.

7. A dual-redundant single-line laser for measuring deformation of spaceborne SAR antennas, characterized in that, The dual-redundant linear laser includes two laser modules, one primary and one backup. The two laser modules are respectively installed in a square housing, with the primary laser module located directly in front of the backup laser module. The two laser modules are offset by 30±0.1mm. Each laser module is assembled from a laser source, a collimation component, a 90° conical reflector component, and a circular lens barrel. The two laser modules are machined on a lathe with a uniform reference bottom surface. The overlap accuracy of the light rays from the two laser modules is ≤1mm at at least 1m, 3m, and 5m.

8. A dual-redundant single-line laser for measuring deformation of a spaceborne SAR antenna according to claim 7, characterized in that, The laser source is a 660nm semiconductor laser diode, and the collimation component is provided with an aspherical lens for collimating the diverging beam output from the semiconductor laser diode along the fast and slow axes.

9. A dual-redundant single-line laser for measuring deformation of a spaceborne SAR antenna according to claim 7, characterized in that, The laser source, collimation component, and 90° conical reflector component are assembled to form a laser component. The outer wall of the laser component is provided with a positioning boss, and the inner wall of the circular lens tube is provided with an annular mounting groove corresponding to the positioning boss. During installation, the positioning boss is engaged into the annular mounting groove.

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