A high-precision optical correction assembly method for a scanning mirror

Abstract

The application relates to a high-precision optical alignment assembly method of a scanning mirror, and belongs to the technical field of laser radar manufacturing equipment, and solves the technical problems of insufficient precision, no compensation for glue shrinkage, low efficiency and high cost of special equipment in the existing scanning mirror assembly. Based on the light reflection principle, the method characterizes the included angle between the scanning mirror and the motor shaft through light path amplification offset, constructs an optical alignment system by using point laser, mirror group and scale receiving plate, completes coarse adjustment and fine adjustment by cooperating with the scanning mirror adjustment jig, makes the positions of the laser spots on the scale receiving plate coincide after the motor rotates 180 degrees, and then completes UV glue curing through the light curing device, and realizes high-precision assembly by combining the glue shrinkage compensation mechanism and the quantitative verification standard. Through the optical alignment method of light path amplification offset, the quantitative adjustment, the verification standard and the glue shrinkage compensation mechanism are combined, high-precision assembly of the scanning mirror and the motor shaft is realized, the glue shrinkage preset offset compensation scheme is established, and the angle offset problem of UV glue curing shrinkage is avoided.

Description

Technical Field

[0001] This invention relates to a high-precision optical calibration assembly method for a scanning mirror, which solves the problems of precision control, shrinkage compensation, and efficient assembly in the assembly process of a LiDAR scanning mirror and a motor shaft plane, and achieves high-precision parallel calibration of the scanning mirror and the motor axis. It belongs to the technical field of LiDAR manufacturing equipment. Background Technology

[0002] As a core device for intelligent sensing, the assembly precision of the scanning mirror in lidar directly determines the detection accuracy, making it a critical process in lidar manufacturing. Currently, the assembly of the scanning mirror and motor shaft mainly employs three methods: mechanical clamping, manual visual adjustment, or customized expensive specialized equipment. However, all of these methods have insurmountable technical drawbacks and cannot meet the high-precision, high-efficiency, and low-cost production requirements of lidar. Specifically: 1. Assembly accuracy is difficult to quantify and control: Machining and installation errors of mechanical fixtures and subjective judgment deviations of manual visual adjustment cannot achieve precise control of the axial angle between the scanning mirror and the motor, resulting in a decrease in the detection accuracy of lidar; 2. No compensation mechanism for UV adhesive curing shrinkage: The UV adhesive used in assembly will shrink during the curing process, causing the angular displacement between the scanning mirror surface and the motor axis. Existing technology lacks a quantitative compensation scheme for this displacement, which further reduces the accuracy after curing. 3. Low assembly efficiency and poor yield: Due to insufficient precision control, repeated disassembly and debugging are required after assembly, which greatly extends the process time, and the final yield is usually less than 80%, increasing production and manufacturing costs. 4. High cost of dedicated equipment: Dedicated calibration equipment customized to improve accuracy can cost hundreds of thousands or even millions of yuan. The high investment threshold makes it difficult to meet the production and R&D needs of most small and medium-sized enterprises and research institutions.

[0003] In summary, existing scanning mirror assembly technology suffers from a contradiction between precision, efficiency, and cost, and there is an urgent need for a highly efficient assembly method that does not require expensive specialized equipment, can achieve quantitative precision control, and can effectively avoid glue shrinkage and offset. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a high-precision optical correction assembly method for scanning mirrors, which solves the technical problems of insufficient precision, lack of shrinkage compensation, low efficiency, and high cost of special equipment in existing assembly methods. This method achieves high-precision, quantitative, and high-efficiency assembly of the scanning mirror and the motor axis, while reducing the equipment investment threshold.

[0005] A high-precision optical calibration assembly method for a scanning mirror is disclosed, applied to the assembly and calibration of a lidar scanning mirror and a motor shaft. The method includes a point laser, a scanning mirror adjustment module, a photopolymerization device, a group of reflectors, a scale receiving plate, and a motor controller. The scanning mirror adjustment module comprises a motor scanning module, a scanning mirror adjustment fixture, and a motor fixing device. The point laser, scanning mirror adjustment module, photopolymerization device, reflector array, scale receiving plate, and motor controller are fixed at specific positions and orientations on the optical panel according to the optical path requirements. This ensures that the point laser beam illuminates the scanning mirror, which is parallel to the axial direction of the scanning motor. After being reflected by the scanning mirror, the point laser enters the reflector array and, after several reflections, finally illuminates the central scale line on the scale receiving plate. Since the scanning mirror in a standard scanning module is parallel to the axial direction of the motor, even after the scanning mirror rotates 180°, the point laser can still illuminate the central scale line on the scale receiving plate. Simultaneously, the ultraviolet light spot from the photopolymerization device illuminates the contact surface between the scanning mirror and the motor shaft. Specifically, the following steps are included: Step 1: Fix the motor of the motor scanning module to the motor fixing device, and put the scanning mirror adjustment fixture on the motor shaft from top to bottom and lock it with the first fastening screw to fix the scanning mirror adjustment fixture and the motor shaft as one piece; Step 2: Apply UV glue to the groove at the end of the motor shaft where the scanning mirror will be placed. Place the scanning mirror in the groove and use a damping elastic cord to flexibly fix the scanning mirror to avoid hard contact that could damage the mirror. Step 3: Adjust the adjusting screws of the scanning mirror adjustment fixture to make the scanning mirror perpendicular to the radial direction of the motor, laying the foundation for subsequent fine adjustment; Step 4: Turn on the point laser to emit laser light to the scanning mirror. Control the motor to rotate through the motor controller so that the laser light is reflected by the scanning mirror to the group of mirrors. After being reflected by the group of mirrors, it shines on the scale receiving plate and records the position of the light spot P1. The number of mirrors in the group of mirrors is determined by the required optical path of the device. Step 5: Control the motor to rotate 180° using the motor controller, and record the position P2 of the laser spot on the scale receiving plate after the laser is reflected by the other side of the scanning mirror; Step 6: Repeatedly adjust the adjusting screws and repeat steps 4 and 5. Adjust the angle α between the scanning mirror and the motor axis using the damping elastic rope until the light spot positions P1 and P2 coincide, that is, the scanning mirror and the motor axis are basically parallel. Step 7: Turn on the light curing device, align the UV purple light spot with the UV glue part at the contact surface between the scanning mirror and the motor shaft to complete curing. If the glue needs thermal curing, place the cured motor scanning module in an oven for thermal curing, and remove the scanning mirror adjustment jig after curing. If the glue used is UV + thermal dual-curing type, place the motor scanning module after UV curing in an oven for thermal curing.

[0006] Step 8: Re-fix the cured motor scanning module on the motor fixing device, repeat Step 4 and Step 5, record the spot positions P1’ and P2’, and calculate the vertical distance d between the two. According to the core formula of trigonometric functions: tan(2α) = (d / 2) / L, where α is the angle between the scanning mirror and the motor axis. Assuming the assembly accuracy requirement is α ≤ β; L is the vertical optical path of the point laser from the scanning mirror to the scale receiving plate, and the qualified standard is derived as d ≤ 2 * L * tan(2β); round down the physical distance d / 2 to obtain the maximum allowable scale interval number N between P1’ and P2’ on the scale receiving plate.

[0007] During verification, if the scale interval number between P1’ and P2’ ≤ N, it is determined that the assembly is qualified; if the scale interval number between P1’ and P2’ > N, it is determined that the assembly is unqualified. Remove the cured glue, reapply UV glue, and repeat Steps 2 to 8 for rework and calibration assembly. The motor scanning module includes a scanning mirror and a motor. The scanning mirror adjustment jig is provided with a damping elastic rope, an adjustment screw, and a first fastening screw.

[0008] During the adjustment process of Step 6, preset an offset. Establish a glue shrinkage database through small-batch tests to complete glue shrinkage compensation. Due to the characteristics of the glue, the glue will shrink to a certain extent before and after curing, which will cause the angle between the scanning mirror and the motor axis direction to become larger before and after curing. Specifically, the interval between P1 and P2 will become larger, and even the interval after curing may exceed N. In this regard, a glue shrinkage database can be established according to small-batch tests (each type of glue completes at least 50 groups of curing tests, record the spot offset before and after curing, and obtain the preset offset by linear fitting). During the adjustment process, preset an offset of several scale intervals in the direction of the 0 scale for the finely adjusted spot. For mainstream UV single-curing glue, preset 1 - 2 scale intervals (2 - 4 mm), and for UV + thermal dual-curing glue, preset 2 - 4 scale intervals (4 - 8 mm). Ensure that the angle between the scanning mirror and the motor axis after curing still meets the requirements and is smaller.

[0009] The point laser is a visible laser for the human eye with a wavelength between 380 nm and 780 nm, and the spot diameter is 2 mm. The mirror group consists of several mirrors, and the number of mirrors is determined by the required reflection optical path of the device and the distance between each mirror.

[0010] The preset offset for shrinkage compensation is a number of scale intervals in the 0-scale direction on the scale receiving plate, with each scale interval corresponding to an offset of 2mm.

[0011] Each component of the calibration device is fixed on the optical panel, and the fixed position and direction are such that the light from the point laser shines on the scanning mirror parallel to the motor axis, and the ultraviolet light spot of the photocuring device precisely covers the UV adhesive contact surface between the scanning mirror and the motor shaft.

[0012] The core calculation formula for assembly calibration is: tan(2α)=(d / 2) / L, where α is the angle between the scanning mirror and the axial direction of the motor, L is the vertical optical path of the point laser from the scanning mirror to the scale receiving plate, and d is the vertical distance between the spot positions P1 and P2 after the motor rotates 180°.

[0013] Based on this formula, if the assembly accuracy target of this invention is set as α≤0.05°, then d≤2Ltan(2×0.05°) must be guaranteed. When L=5000mm, d≤17.45mm is calculated. Considering system error and ease of operation, the actual verification standard is determined to be d≤16mm, that is, the scale interval between P1 and P2 on the scale receiving plate is ≤8 (the interval between two adjacent scale lines is 2mm).

[0014] A high-precision optical calibration assembly method for a scanning mirror, applied to the assembly and calibration of a lidar scanning mirror and a motor shaft, includes a point laser, a scanning mirror adjustment module, a photopolymerization device, a group of reflectors, a motor controller, a high-resolution CCD vision camera, a piezoelectric ceramic micro-displacement actuator, and a visual feedback closed-loop control system. The method is characterized by the following steps: Step 1: Fix the motor of the motor scanning module to the motor fixing device, and put the automatic scanning mirror adjustment fixture on the motor shaft from top to bottom and lock it with the first fastening screw to fix the two. Step 2: Apply UV glue to the groove at the end of the motor shaft where the scanning mirror will be placed, place the scanning mirror on the groove, and flexibly fix the scanning mirror with a damping elastic rope. Step 3: Coarsely adjust the angle of the scanning mirror using a piezoelectric ceramic micro-displacement actuator to keep the scanning mirror perpendicular to the radial direction of the motor; Step 4: Turn on the point laser to emit laser light to the scanning mirror. Control the motor to rotate through the motor controller so that the laser light is reflected by the scanning mirror to the group of mirrors. After being reflected by the group of mirrors, it illuminates the acquisition area of ​​the CCD vision camera. The CCD vision camera extracts the sub-pixel level coordinates of the laser spot and marks it as P1, and transmits it to the visual feedback closed-loop control system. Step 5: Control the motor to rotate 180° via the motor controller. The CCD vision camera extracts the sub-pixel coordinates of the laser spot reflected from the other side of the scanning mirror and marks it as P2. This data is then transmitted to the visual feedback closed-loop control system. Step Six: The visual feedback closed-loop control system compares the offset of coordinates P1 and P2 with the 0-scale reference coordinate and outputs a control signal to the piezoelectric ceramic micro-displacement actuator. The piezoelectric ceramic micro-displacement actuator automatically adjusts the angle α between the scanning mirror and the motor axis until the light spot position P1 and P2 collected by the CCD vision camera coincide. At the same time, the system automatically retrieves the glue shrinkage database and, during the fine adjustment process, presets an offset towards the 0-scale direction to complete the glue shrinkage compensation. Step 7: Turn on the light curing device and align the UV light spot with the UV adhesive on the contact surface between the scanning mirror and the motor shaft to complete the curing. If the adhesive needs to be heat-cured, place the UV-cured motor scanning module in an oven for heat curing. After curing, remove the automatic scanning mirror adjustment fixture. Step 8: Re-fix the cured motor scanning module onto the motor fixing device, repeat steps 4 and 5, and have the CCD vision camera collect the sub-pixel coordinates of the light spot positions P1' and P2'. The system automatically calculates the vertical distance d between them. According to the formula: tan (2α)=(d / 2) / L, where α is the angle between the scanning mirror and the motor axis, assuming the assembly accuracy requirement is α≤β, and L is the vertical optical path of the point laser from the scanning mirror to the acquisition area of ​​the CCD vision camera, the qualified standard is derived to be d≤2Ltan (2β). The physical distance d / 2 is rounded down to obtain the maximum allowable pixel offset N. If the pixel offset between P1' and P2' is ≤ N, the assembly is deemed qualified; if the pixel offset between P1' and P2' is > N, the assembly is deemed unqualified. Remove the cured adhesive, reapply UV adhesive, and repeat steps two to eight for rework and calibration assembly.

[0015] This invention achieves high-precision assembly of the scanning mirror and motor shaft by using an optical calibration method that amplifies the offset in the optical path, combined with quantization adjustment, verification standards, and shrinkage compensation mechanisms. Compared with existing technologies, it has the following significant technical advantages: 1. High and quantifiable assembly precision: The minute angle between the scanning mirror and the motor axis is converted into a visual spot offset on the scale receiving plate. The assembly precision is quantitatively controlled by formulas to achieve high precision, completely solving the problem of insufficient precision of manual visual inspection and mechanical fixtures, and effectively improving the detection accuracy of lidar. 2. Effectively avoid glue shrinkage angle deviation: Establish a glue shrinkage database and set a preset offset compensation scheme to quantitatively compensate for the defects of UV glue curing shrinkage, avoid the decrease in accuracy after curing, and ensure the stability of assembly accuracy. 3. High assembly efficiency and improved yield: No need for repeated disassembly and debugging, rapid coarse and fine adjustments are achieved through the optical system, which greatly shortens the process time. Moreover, the quantitative verification standards ensure assembly consistency, which greatly improves the yield compared with the existing technology (<80%). This patented solution can achieve a first-pass yield of ≥96%. 4. Low equipment investment cost: No need to customize expensive special equipment. The calibration system can be built with conventional optical components such as point lasers, reflector groups, and scale receiving plates and simple adjustment fixtures. The equipment investment threshold is low, which can meet the production and R&D needs of small and medium-sized enterprises and scientific research institutions. 5. Easy to operate and highly versatile: The entire assembly process is simple to operate and the adjustment method is intuitive. It can also adjust the reflected optical path and preset offset according to the scanning mirror specifications and adhesive type of different LiDAR, making it suitable for scanning mirror assembly in various scenarios and highly versatile. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is an overall structural diagram of a high-precision optical correction assembly method for a scanning mirror according to the present invention.

[0018] Figure 2 This is a structural diagram of the scanning mirror adjustment module in a high-precision optical correction assembly method for scanning mirrors according to the present invention.

[0019] Figure 3 This is a structural diagram of the motor scanning module in a high-precision optical correction assembly method for a scanning mirror according to the present invention.

[0020] Figure 4 This is a structural diagram of the scanning mirror adjustment fixture in a high-precision optical correction assembly method for scanning mirrors according to the present invention.

[0021] Figure 5 This is a structural diagram of the motor fixing device in a high-precision optical correction assembly method for a scanning mirror according to the present invention.

[0022] Figure 6 This is a structural diagram of the photopolymerization device in a high-precision optical correction assembly method for a scanning mirror according to the present invention.

[0023] Figure 7 This is a structural diagram of the scale receiving plate in the high-precision optical correction assembly method for a scanning mirror according to the present invention.

[0024] In the diagram: 1-Point laser, 2-Scanning mirror adjustment module, 3-Photocuring device, 4-Reflector group, 5-Scale receiving plate, 6-Motor controller, 21-Motor scanning module, 211-Scanning mirror, 212-Motor, 22-Scanning mirror adjustment fixture, 221-Damping elastic rope, 222-Adjusting screw, 224-First fastening screw, 23-Motor fixing device, 231-Motor clamp, 232-Second fastening screw, 31-UV protective cover, 32-UV lamp. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and 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. Example

[0026] This embodiment provides a high-precision optical correction assembly method for a LiDAR scanning mirror, adapted for the assembly of a scanning mirror in a small LiDAR system. It includes a point laser 1, a scanning mirror adjustment module 2, a photopolymerization device 3, a group of reflectors 4, a scale receiving plate 5, and a motor controller 6. The scanning mirror adjustment module 2 includes a motor scanning module 21, a scanning mirror adjustment fixture 22, and a motor fixing device 23. The motor fixing device 23 includes a motor clamp and a second fastening screw. The point laser is a red laser with a wavelength of 650nm and a spot diameter of 2mm, with an output power of... The system has a power rating of 5mW, a scanning mirror size of 20*15mm, a reflector group consisting of 3 mirrors, a motor shaft diameter of 30mm, a maximum speed of 1500rpm, a rotational accuracy of ±0.01°, uses conventional UV single-curing adhesive with a curing time of 10s, a reflected optical path of 5000mm for the calibration device, a scale receiving plate size of 80mm×50mm, 2mm spacing between black scale lines, a centered baseline, and a total of 15 scale lines (-7 to +7). The assembly target is that the angle α between the scanning mirror and the motor axis is ≤0.05°. The scanning mirror selected in this embodiment is a high-parallelism double-sided reflector, whose wedge angle error is much smaller than the system accuracy requirements.

[0027] The specific assembly steps are as follows: Step 1: Fixture fixing: Fix the 30mm diameter motor 212 in the slot of the motor fixing device 23 with bolts to ensure that the motor does not wobble; put the scanning mirror adjustment fixture 22 on the motor shaft, and tighten the first fastening screw 224 with an Allen wrench to fix the fixture and the motor shaft coaxially.

[0028] Step 2: Applying adhesive and fixing the lens: Use a dispensing pen to apply an appropriate amount of UV adhesive to the groove of the scanning mirror at the end of the motor shaft. The adhesive should be applied evenly to a thickness of 0.1mm. Place the 20*15mm scanning mirror 211 stably on the groove. Put the damping elastic rope 221 on both sides of the scanning mirror 211 and adjust the tightness of the elastic rope to achieve flexible fixing of the scanning mirror.

[0029] Step 3: Coarse adjustment of verticality: Use a hex screwdriver to slowly adjust the adjusting screw 222 on the scanning mirror adjustment fixture 22. Visually observe to ensure that the scanning mirror 211 is perpendicular to the radial direction of the motor and has no obvious tilt.

[0030] Step 4: Initial measurement of laser spot: Turn on the spot laser 1, adjust the laser output port so that the red spot laser is perpendicularly illuminating the center of the scanning mirror 211; operate the motor controller 6 to control the motor 212 to rotate at low speed, so that the laser is reflected by the scanning mirror 211 to the reflector group 4 composed of 4 reflectors. After 4 reflections, the total optical path is 5000mm and it illuminates the scale receiving plate 5. Record the scale position P1 corresponding to the center of the spot, and the scale is 6.

[0031] Step 5: 180° rotation retest: The motor controller 6 sends a command to make the motor 212 rotate 180° around the axis. After the laser is reflected by the center of the other side of the scanning mirror 211, it is irradiated on the scale receiving plate 5 by the reflector group 4. The center position of the light spot P2 is recorded, the scale is -5, the two are 11 lines apart, the interval is 22mm, they do not overlap yet and are greater than 16mm, so fine adjustment is required.

[0032] Step Six: Fine-tuning Parallelism: Slowly adjust the adjusting screw 222, rotating it 1 / 4 turn each time. After adjustment, repeat steps four and five to gradually reduce the offset of P1 and P2. After three adjustments, after the motor rotates 180°, the positions of the light spots P1 and P2 both fall on the 0 mark of the scale receiving plate 5, and the two are completely coincident. The scanning mirror is basically parallel to the motor axis.

[0033] Step 7: Glue curing: Turn on the UV lamp 32 of the light curing device 3. The UV lamp 32 is equipped with a UV protective cover 31 so that the ultraviolet light spot accurately covers the glue contact surface between the scanning mirror 211 and the motor shaft. Turn on the UV curing for 10 seconds to complete the glue curing. After curing, use an Allen wrench to loosen the first fastening screw 224 and remove the scanning mirror adjustment fixture 22.

[0034] Step 8: Quantitative verification: Re-fix the cured motor scanning module 21 onto the motor fixing device 23, repeat steps 4 and 5, record P1' as scale 2 and P2' as scale -2, the scale interval between P1' and P2' is 4, which meets the judgment standard of less than 8 scale intervals, and the assembly is judged to be qualified.

[0035] Glue shrinkage compensation: The UV adhesive used in this embodiment was tested in a small batch. The spot offset caused by curing shrinkage was 8mm at 4 scale intervals. Considering that the spot offset is affected by both sides of the scanning mirror, in step six of the subsequent assembly of products of the same specification, the finely adjusted spot P1 was preset at 2 intervals below the 0 scale, that is, at the -2 scale. After curing, the spot offset was canceled out, still meeting the assembly standard, and the included angle was smaller than that without glue shrinkage compensation. Example

[0036] This embodiment is adapted for the assembly of a scanning mirror of a scientific research lidar. The scanning mirror is 30*25mm in size, the motor shaft diameter is 30mm, the maximum speed is 1500rpm, the rotation accuracy is ±0.01°, and a UV + heat curing adhesive is used. The UV curing time is 10s, the heat curing time is 30min@60℃, the reflected optical path of the calibration device is set to 5000mm, the assembly target α≤0.05°, and the spot offset caused by adhesive shrinkage is 12mm, i.e., 6 scale intervals.

[0037] The assembly steps in this embodiment are basically the same as those in embodiment 1, except that: 1. In the adhesive curing stage of step seven, after UV curing for 10 seconds, place the motor scanning module 21 in a 60℃ oven for heat curing for 30 minutes to complete the curing process. 2. In the fine-tuning parallelism stage of step six, based on the glue shrinkage database, the finely tuned spot P1 is preset at three intervals below the 0 mark, i.e., at the -3 mark, to complete the glue shrinkage compensation. 3. In the quantitative verification stage, the offset of P1 and P2 is 1 interval, which is less than 8 intervals, indicating that the assembly is qualified. The angle between the scanning mirror and the motor axis is detected to be 0.01°, which meets the target of α≤0.05°. Example

[0038] This embodiment is an automation upgrade based on the solution in Embodiment 1. The core modification is as follows: 1. Replace the scale receiving plate 5 with a 12-megapixel high-resolution CCD vision camera (with an industrial lens and image acquisition card), with a spot positioning accuracy of ≤0.1mm, to achieve sub-pixel level automatic extraction of laser spot coordinates; 2. Replace the manual adjustment screw 222 of the scanning mirror adjustment fixture 22 with a piezoelectric ceramic micro-displacement actuator with a displacement accuracy ≥ 0.01μm and a response frequency of 100Hz; 3. Establish a visual feedback closed-loop system: CCD acquires the coordinates of the light spot → compares with the 0-scale reference coordinates → outputs control signals to the piezoelectric ceramic micro-displacement actuator → adjusts the scanning mirror angle, with a closed-loop adjustment cycle ≤0.5s; 4. Glue shrinkage compensation: The system automatically retrieves the glue shrinkage database to automatically adjust the preset offset.

[0039] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A high-precision optical calibration assembly method for a scanning mirror, applied to the assembly and calibration of a lidar scanning mirror and a motor shaft, comprising a point laser, a scanning mirror adjustment module, a photopolymerization device, a group of reflectors, a scale receiving plate, and a motor controller, wherein the scanning mirror adjustment module comprises a motor scanning module, a scanning mirror adjustment fixture, and a motor fixing device, characterized in that... Includes the following steps: Step 1: Fix the motor of the motor scanning module to the motor fixing device, and put the scanning mirror adjustment fixture on the motor shaft from top to bottom and lock it with the first fastening screw to fix the two. Step 2: Apply UV glue to the groove at the end of the motor shaft where the scanning mirror will be placed, place the scanning mirror on the groove, and flexibly fix the scanning mirror with a damping elastic rope. Step 3: Adjust the adjusting screws of the scanning mirror adjustment fixture to make the scanning mirror perpendicular to the radial direction of the motor; Step 4: Turn on the spot laser to emit laser light to the scanning mirror. Control the motor to rotate through the motor controller so that the laser light is reflected by the scanning mirror to the group of mirrors, and then reflected by the group of mirrors to illuminate the scale receiving plate. Record the position of the light spot P1. Step 5: Control the motor to rotate 180° using the motor controller, and record the position P2 of the laser spot on the scale receiving plate after the laser is reflected by the other side of the scanning mirror; Step Six: Repeatedly adjust the adjusting screws and repeat steps four and five, and adjust the angle α between the scanning mirror and the motor axis using the damping elastic rope until the light spot positions P1 and P2 coincide. Step 7: Turn on the light curing device and align the UV light spot with the UV adhesive area on the contact surface between the scanning mirror and the motor shaft to complete the curing. After curing, remove the scanning mirror and adjust the fixture. Step 8: Re-fix the cured motor scanning module onto the motor mounting device, repeat steps 4 and 5, record the positions of the light spots P1' and P2', and calculate the vertical distance d between them; According to the formula: tan(2α)=(d / 2) / L, where α is the angle between the scanning mirror and the motor axis, and the assembly accuracy requirement is assumed to be α≤β; L is the vertical optical path of the point laser from the scanning mirror to the scale receiving plate. The qualified standard is derived to be d≤2*L*tan(2β). The physical distance d / 2 is rounded down to obtain the maximum allowable number of scale intervals between P1' and P2' on the scale receiving plate as N. During verification, if the number of scale intervals between P1' and P2' is ≤ N, the assembly is deemed qualified; if the number of scale intervals between P1' and P2' is > N, the assembly is deemed unqualified. Remove the cured adhesive, reapply UV adhesive, and repeat steps two to eight for rework and calibration assembly.

2. The high-precision optical correction assembly method for a scanning mirror according to claim 1, characterized in that: The motor scanning module includes a scanning mirror and a motor, and the scanning mirror adjustment fixture is equipped with a damping elastic rope, an adjustment screw and a first fastening screw.

3. The high-precision optical correction assembly method for a scanning mirror according to claim 1, characterized in that: In the adjustment process of step six, a preset offset is set, and a glue shrinkage database is established through small-batch experiments to complete the glue shrinkage compensation.

4. The high-precision optical correction assembly method for a scanning mirror according to claim 1, characterized in that: The point laser is a visible light laser source with a spot diameter of 2 mm. The point laser is a low divergence angle parallel laser emission source with a collimating lens group. The reflector group consists of several reflectors, and the number of reflectors is determined by the required optical path length of the device.

5. The high-precision optical correction assembly method for a scanning mirror according to claim 3, characterized in that: The preset offset for shrinkage compensation is a number of scale intervals in the 0-scale direction on the scale receiving plate, with each scale interval corresponding to an offset of 2mm.

6. The high-precision optical correction assembly method for a scanning mirror according to claim 1, characterized in that: The point laser, scanning mirror adjustment module, photocuring device, reflector group, scale receiving plate and motor controller are all fixed on the optical panel. The fixed position and direction ensure that the light from the point laser illuminates the scanning mirror parallel to the motor axis, and the ultraviolet light spot of the photocuring device accurately covers the UV adhesive contact surface between the scanning mirror and the motor shaft.

7. A high-precision optical calibration assembly method for a scanning mirror, applied to the assembly and calibration of a lidar scanning mirror and a motor shaft, comprising a point laser, a scanning mirror adjustment module, a photopolymerization device, a group of reflectors, a motor controller, a high-resolution CCD vision camera, a piezoelectric ceramic micro-displacement actuator, and a visual feedback closed-loop control system, characterized in that... Includes the following steps: Step 1: Fix the motor of the motor scanning module to the motor fixing device, and put the automatic scanning mirror adjustment fixture on the motor shaft from top to bottom and lock it with the first fastening screw to fix the two. Step 2: Apply UV glue to the groove at the end of the motor shaft where the scanning mirror will be placed, place the scanning mirror on the groove, and flexibly fix the scanning mirror with a damping elastic rope. Step 3: Coarsely adjust the angle of the scanning mirror using a piezoelectric ceramic micro-displacement actuator to keep the scanning mirror perpendicular to the radial direction of the motor; Step 4: Turn on the point laser to emit laser light to the scanning mirror. Control the motor to rotate through the motor controller so that the laser light is reflected by the scanning mirror to the group of mirrors. After being reflected by the group of mirrors, it illuminates the acquisition area of ​​the CCD vision camera. The CCD vision camera extracts the sub-pixel level coordinates of the laser spot and marks it as P1, and transmits it to the visual feedback closed-loop control system. Step 5: Control the motor to rotate 180° via the motor controller. The CCD vision camera extracts the sub-pixel coordinates of the light spot after the laser is reflected by the other side of the scanning mirror and marks it as P2. The coordinates are then transmitted to the visual feedback closed-loop control system. Step Six: The visual feedback closed-loop control system compares the offset of coordinates P1 and P2 with the 0-scale reference coordinate and outputs a control signal to the piezoelectric ceramic micro-displacement actuator. The piezoelectric ceramic micro-displacement actuator automatically adjusts the angle α between the scanning mirror and the motor axis until the light spot position P1 and P2 captured by the CCD vision camera coincide. At the same time, the system automatically retrieves the glue shrinkage database and, during the fine adjustment process, presets an offset in the 0-scale direction to complete the glue shrinkage compensation. Step 7: Turn on the light curing device and align the UV light spot with the UV adhesive area on the contact surface between the scanning mirror and the motor shaft to complete the curing. After curing, remove the automatic scanning mirror adjustment fixture. Step 8: Re-fix the cured motor scanning module onto the motor fixing device, repeat steps 4 and 5, and have the CCD vision camera collect the sub-pixel level coordinates of the light spot positions P1' and P2'. The system automatically calculates the vertical distance d between them. According to the formula: tan (2α)=(d / 2) / L, where α is the angle between the scanning mirror and the motor axis, assuming the assembly accuracy requirement is: α≤β, and L is the vertical optical path of the point laser from the scanning mirror to the CCD vision camera acquisition area, the qualified standard is derived to be d≤2Ltan (2β). The physical distance d / 2 is rounded down to obtain the maximum allowable pixel offset N. If the pixel offset between P1' and P2' is ≤ N, the assembly is deemed qualified; if the pixel offset between P1' and P2' is > N, the assembly is deemed unqualified. Remove the cured adhesive, reapply UV adhesive, and repeat steps two to eight for rework and calibration assembly.

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