Laser sensor for rotary 3D profile measurement system

Abstract

The invention discloses a laser sensor for a rotary 3D profile measurement system, and belongs to the technical field of 3D profile measurement sensors. Comprising a cavity seat, a detection module is fixed on the inner side of the cavity seat, the detection module comprises a laser emission module, an included angle execution module, a light path folding module, an imaging module and a signal processing module, the laser emission module comprises a laser semiconductor and a focusing lens, and the included angle execution module comprises an angle adjusting unit. An angle-adjustable reflecting mirror is fixed at the angle adjusting end of the angle adjusting unit, the angle-adjustable reflecting mirror is arranged on a light emitting path of the focusing lens, and the signal processing module is electrically connected with the linear array CMOS sensor. According to the laser sensor for the rotary 3D profile measurement system, the requirements of the three-dimensional profile measurement system for measurement in different height ranges and efficient detection of multi-welding-seam characteristics under different measurement distances are met while it is guaranteed that the diameter of a rotary scanning circle is adjustable along with the distance and the size is compact.

Description

Technical Field

[0001] This invention specifically relates to a laser sensor for a rotary 3D contour measurement system, belonging to the technical field of 3D contour measurement sensor. Background Technology

[0002] Laser displacement sensors are non-contact measuring devices widely used in industrial inspection, quality control, and other fields. Traditional laser displacement sensors typically employ a fixed optical path design. After laser emission, it is focused by a lens and directly illuminates the object being measured. Then, an imaging system images the reflected light onto a CMOS sensor. For example, Chinese Patent Publication No. CN115031658B discloses a 3D laser imaging system, including a 3D laser displacement sensor, an adapter protector, a photoelectric sensor, a power supply, and a computer. This 3D laser imaging system has a simple structure and adds temperature compensation and high-speed measurement functions. Another example is a laser displacement sensor with a fixed optical path. After laser emission, it is focused by a fixed lens to form a laser line or spot at a fixed position. The scanning range is fixed by the optical path structure and cannot be adjusted. It uses a linear optical path design and is relatively large. Typical examples include Keyence LK series and Omron ZX series. Another example is an area array CMOS sensor. S3D profilometers, which use area array CMOS sensors for 3D profile measurement, are costly, have complex data processing, and are relatively large, making them unsuitable for compact applications. A typical example is the Gocator series. Furthermore, traditional rotating scanning laser profilometers produce a fixed circle diameter during rotation, which does not change with the measurement distance. When the measurement distance changes, the fixed circle diameter cannot adapt to the measurement needs of different height ranges. For example, it cannot measure small height features at close range with a smaller circle diameter, or large height features at long distance. Moreover, current technology cannot achieve adaptive circle diameter changes with distance, resulting in poor application flexibility. For long-distance sensors, the optical path distance from laser emission to the measured object is long; for example, a typical laser displacement sensor is 80-120mm long. When integration into compact devices (such as robot end effectors and automated production lines), size limitations become a bottleneck. Summary of the Invention

[0003] To address the aforementioned issues, this invention proposes a laser sensor for a rotary 3D contour measurement system. While ensuring that the diameter of the rotating scanning circle is adjustable with distance, the sensor is compact, and the cost is low, it also meets the requirements of the 3D contour measurement system for measuring different height ranges at different measurement distances and for efficient detection of multiple weld seam features.

[0004] The laser sensor for a rotary 3D contour measurement system of the present invention includes a cavity base, wherein a detection module is fixed inside the cavity base, and the detection module includes: A laser emitting module includes a laser semiconductor and a focusing lens, wherein the focusing lens is disposed on the light output path of the laser semiconductor; the laser semiconductor is used to emit a laser beam with a laser power of 5-20mW and a wavelength of 650nm or 780nm; the focusing lens is disposed on the light output path of the laser semiconductor to focus the laser beam with a focal length of 8-15mm and a focused spot diameter of 0.05-0.2mm; An angle-adjusting module includes an angle-adjusting unit. An adjustable-angle reflector is fixed to the angle-adjusting end of the unit. The adjustable-angle reflector is positioned on the light-emitting path of the focusing lens to reflect the focused laser beam to the object being measured. The angle of the adjustable-angle reflector can be adjusted by the angle-adjusting unit and then fixed. The angle α between the adjustable-angle reflector and the axis of the cavity seat is adjustable from 5° to 20°. By adjusting the angle α, the diameter of the circle formed during rotational scanning can be controlled to vary with the measurement distance. The variation pattern is: the closer to the sensor, the smaller the circle diameter; the farther from the sensor, the larger the circle diameter. The effective measurement range is 350±250mm (i.e., 100mm-600mm). At the near end (100mm distance), the circle diameter is 35mm, and at the far end (400mm distance), the circle diameter is 100mm. An optical path folding module is disposed on the light output path of an adjustable angle reflector; the optical path folding module reflects the laser beam to the object under test; the optical path folding module includes at least one reflector for folding the laser beam reflected by the adjustable angle reflector, the folded length of which is 40-60mm, so as to reduce the size of the sensor; The imaging module includes an aspherical imaging lens and a linear CMOS sensor. The linear CMOS sensor is disposed on the image plane of the aspherical imaging lens. The aspherical imaging lens receives and images the laser beam reflected from the object being measured. The aspherical imaging lens adopts an aspherical structure to reduce aberrations and improve image quality. The aspherical imaging lens is used to receive and image the laser beam reflected from the object being measured, with a focal length of 20-30mm and an imaging magnification of 0.5-2.0. The linear CMOS sensor is used to receive the imaged light signal and convert it into an electrical signal, with a pixel count of 1024-4096 and a measurement frequency of 3000-10000Hz to meet high-speed measurement requirements. The signal processing module is electrically connected to the linear CMOS sensor; it is used to process electrical signals and output displacement measurement results with a measurement accuracy of ±0.01-0.05mm.

[0005] Furthermore, the top of the cavity seat is fixed and coaxially arranged with the rotating end of the rotating platform; when the cavity seat rotates around the axis, since the adjustable angle reflector has an angle with the axis, the optical path folding module forms a circle in space for the trajectory of the point laser, and the diameter of the circle changes with the measurement distance.

[0006] Furthermore, the signal processing module is composed of an FPGA. The signal processing module receives the electrical signal from the linear CMOS sensor, converts the analog signal into a digital signal through A / D conversion, and calculates the displacement d of the measured object according to the triangulation formula, d=(x-x0)×M×tan(θ_tri); where x is the position of the light spot on the linear CMOS, x0 is the reference position, M is the imaging magnification, and θ_tri is the triangulation angle.

[0007] Furthermore, the angle adjustment unit includes a backing plate fixed to the inner side of the cavity seat, an angle adjustment plate attached to the front end of the backing plate, and an adjustable angle reflector fixed to the front end of the angle adjustment plate; the angle adjustment plate has multiple arc-shaped guide grooves, and limit bolts or guide posts are provided inside the arc-shaped guide grooves; the limit bolts are screwed to the backing plate, and the angle of the adjustable angle reflector is manually adjusted and then fixed by the limit bolts; the guide post is fixed to the backing plate and connected to an angle adjustment driver; the adjustable angle reflector achieves angle adjustment through the angle adjustment unit. Section; The angle adjustment driver is a worm gear manual adjustment mechanism, which realizes precise adjustment of the included angle α, with an adjustment resolution of <0.01°; When manually adjusting the angle, loosen the limit bolt and rotate the arc-shaped guide groove of the angle adjustment plate along the limit bolt. After the angle adjustment is completed, tighten the limit bolt and the backing plate again to lock the position of the angle adjustment plate; After the angle adjustment is completed, or by rotating the knob, drive the worm of the worm gear manual adjustment mechanism to rotate. The worm drives the angle adjustment plate to rotate synchronously through the worm gear, thereby realizing the angle adjustment of the adjustable reflector.

[0008] Furthermore, the angle adjustment driver includes a rotating shaft fixed at the center of the angle adjustment plate; the rotating shaft is rotatably mounted to the backing plate via bearings; the rotating shaft is connected to a drive motor on the backing plate via a transmission mechanism; the transmission mechanism is a transmission mechanism composed of a synchronous pulley and a synchronous belt, or a transmission mechanism composed of a gear transmission box; during electric angle adjustment, the drive motor drives the rotating shaft to rotate via the transmission mechanism, and the rotating shaft drives the angle adjustment plate to rotate synchronously, thereby synchronously driving the adjustable angle reflector to rotate, so as to change the reflection angle; when the angle adjustment plate rotates, the arc-shaped guide groove of the angle adjustment plate is guided to rotate along the guide post.

[0009] Furthermore, the optical path folding module includes one or more fixed reflectors; the optical path folding module is a common optical and optical path structure; the laser beam emitted by the laser emission module is reflected by the adjustable-angle reflector, enters the optical path folding module to complete optical folding, and is reflected to the object under test. The received beam reflected by the object under test returns along the original folded optical path; for example, the optical path folding module uses two reflectors (a first reflector and a second reflector), the first reflector is used to reflect the laser beam reflected by the adjustable-angle reflector to the second reflector, and the second reflector is used to reflect the laser beam to the object under test; or three reflectors (with a third reflector added) are used to further reduce the sensor size.

[0010] Furthermore, it also includes a coupling error compensation module, which has a built-in coupling error model for angle, optical path, and imaging; the rotating end of the angle adjustment unit integrates an angle sensor, which forms a closed-loop control with the angle adjustment driver, and the angle sensor synchronizes real-time angle data to the coupling error compensation module; the coupling error compensation module is connected to the signal processing module, and the inputs of the coupling error model include the real-time included angle of the adjustable angle reflector, the measurement distance, and the internal temperature, and the outputs are the optical path compensation value, the triangulation reference parameter correction value, and the spot centroid offset compensation value; the coupling error compensation module dynamically compensates the displacement calculation results according to the real-time inputs to eliminate coupling errors caused by changes in included angle, changes in optical path of folded optical paths, and temperature drift.

[0011] Furthermore, it also includes a transmit / receive common path matching module, which includes a polarization beam splitting unit and an optical axis follower calibration unit; the polarization beam splitting unit includes a polarization beam splitting prism and a quarter-wave plate, the polarization beam splitting prism is disposed between the laser emission module and the angle-adjustable execution module, and the quarter-wave plate is disposed between the polarization beam splitting prism and the angle-adjustable execution module; a set of beam constraint adaptation units is fixed at both the beginning and end of the optical path folding module, the beam constraint adaptation unit is composed of an aperture and a beam constraint adaptation unit; the aperture of the aperture matches the beam diameter within the full adjustment range of the α angle.

[0012] Furthermore, the optical path folding module is a Z-type multi-level folded optical path, an M-type multi-level folded optical path, or a U-type folded optical path.

[0013] Furthermore, the signal processing module incorporates a rotation-linked scanning control module, which achieves hardware synchronization with the angle encoder of the rotating platform, with a synchronization error of <1μs, and supports the following two scanning modes: Fixed-angle rotation scanning mode: The included angle α of the adjustable-angle reflector is locked, and the sensor rotates to form a circular scanning trajectory that changes linearly with the measurement distance. Dynamic linkage variable diameter scanning mode: During the sensor rotation, the included angle α of the adjustable angle reflector is adjusted in real time according to the rotation angle to realize variable diameter scanning, spiral scanning, directional fan-shaped scanning, and irregular contour following scanning. During the dynamic adjustment of the α angle, the transmit and receive common path matching module always ensures the matching of the transmit and receive fields of view.

[0014] Compared with the prior art, the laser sensor of the present invention for a rotating 3D contour measurement system has the following advantages: 1. The scanning circle diameter is adjustable with distance, providing high application flexibility: An adjustable-angle reflector forms an angle α (5°-20°) with the axis. When the sensor rotates, the diameter of the scanning circle changes with the measurement distance due to the presence of angle α: the closer the distance, the smaller the circle; the farther the distance, the larger the circle. By adjusting the angle α, the scanning circle diameter at different measurement distances can be controlled to adapt to measurement needs in different height ranges. Adjusting the reflector angle can also control the scanning circle diameter at different measurement distances, adapting to measurement needs in different height ranges and improving application flexibility.

[0015] 2. The optical path folding structure can fold the optical path with a straight distance of 80-120mm into 40-60mm, making it compact, easy to integrate, and reducing the volume by about 40-50%, which is beneficial for integration into compact equipment (such as robot end effectors and automated production lines).

[0016] 3. Lower cost and high cost performance: Using a linear CMOS sensor (1024-4096 pixels) instead of an area CMOS sensor reduces the cost by about 30-50%; at the same time, it simplifies data processing and reduces system complexity.

[0017] 4. High measurement accuracy and excellent performance: The aspherical imaging lens reduces aberrations (RMS wavefront error <λ / 4), improves imaging quality, and achieves a measurement accuracy of ±0.01-0.05mm, which is comparable to that of a CMOS profilometer (±0.01mm). Compared with traditional fixed optical path sensors (±0.02mm), the accuracy is improved by about 50%.

[0018] 5. Fast measurement speed to meet high-speed requirements: The linear CMOS sensor has a measurement frequency of 3000-10000Hz, which is 2.5 times faster than the area array CMOS 3D profilometer, meeting the requirements of high-speed measurement and suitable for dynamic measurement scenarios.

[0019] 6. By combining the adjustable angle reflector and the optical path folding structure, a synergistic effect is achieved, simultaneously realizing the technical effects of adjustable scanning range and compact size: the diameter of the rotating scanning circle can be adjusted with distance through the angle execution module, thereby meeting a large effective range. Moreover, the optical path length caused by large distances in the range is solved by the optical path folding module, thus avoiding the need for a large reduction in the physical size of the sensor.

[0020] 7. Wide range of applications: It can be widely used in applications such as rotary 3D contour measurement with adjustable scanning circle diameter and weld seam location. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the arrangement of the modules of the laser sensor of the present invention along the optical path.

[0022] Figure 2 This is a schematic diagram of the connection structure between the signal processing module and each electronic control module in Embodiment 1 of the present invention.

[0023] Figure 3 This is a schematic diagram of the laser sensor structure of a reflector of the present invention.

[0024] Figure 4 This is a schematic diagram of the angle execution module for manually adjusting the included angle according to the present invention.

[0025] Figure 5 This is a schematic diagram of another manually adjustable angle execution module structure according to the present invention.

[0026] Figure 6 This is a schematic diagram of the angle adjustment module structure of the present invention.

[0027] Figure 7 This is a schematic diagram of the connection structure between the signal processing module and each electronic control module in Embodiment 6 of the present invention.

[0028] Figure 8 This is a schematic diagram of the connection structure between the signal processing module and each electronic control module in Embodiment 7 of the present invention.

[0029] Figure 9 This is a schematic diagram of the connection structure between the signal processing module and each electronic control module in Embodiment 8 of the present invention.

[0030] Reference numerals: 1. Cavity seat; 2. Laser semiconductor; 3. Focusing lens; 4. Angle adjustment unit; 5. Adjustable angle reflector; 6. Optical path folding module; 7. Aspherical imaging lens; 8. Linear array CMOS sensor; 9. Backing plate; 10. Angle adjustment plate; 11. Arc-shaped guide groove; 12. Limiting bolt; 13. Guide column; 14. Worm gear manual adjustment mechanism; 15. Drive motor; 16. Gear transmission box. Detailed Implementation

[0031] Example 1: like Figures 1 to 6 The laser sensor shown for a rotary 3D contour measurement system includes a cavity 1, on the inner side of which a detection module is fixed. The detection module includes: A laser emitting module includes a laser semiconductor 2 and a focusing lens 3. The focusing lens 3 is disposed on the light output path of the laser semiconductor 2. The laser semiconductor 2 is used to emit a laser beam with a laser power of 5-20mW and a wavelength of 650nm or 780nm. The focusing lens 3 is disposed on the light output path of the laser semiconductor 2 and is used to focus the laser beam with a focal length of 8-15mm and a focused spot diameter of 0.05-0.2mm. The included angle execution module includes an angle adjustment unit 4. An adjustable angle reflector 5 is fixed to the angle adjustment end of the angle adjustment unit 4. The adjustable angle reflector 5 is positioned on the light output path of the focusing lens 3 and is used to reflect the focused laser beam to the object being measured. The angle of the adjustable angle reflector 5 can be adjusted by the angle adjustment unit 4 and then fixed. The angle α between the adjustable angle reflector 5 and the axis of the cavity seat 1 is adjustable from 5° to 20°. By adjusting the angle α, the diameter of the circle formed during rotational scanning can be controlled to change with the measurement distance. The variation pattern is: the closer to the sensor, the smaller the circle diameter; the farther from the sensor, the larger the circle diameter. The effective measurement range is 350±250mm (i.e., 100mm-600mm). At the near end (100mm distance), the circle diameter is 35mm, and at the far end (400mm distance), the circle diameter is 100mm. The optical path folding module 6 is disposed on the light output path of the adjustable angle reflector 5; the optical path folding module 6 reflects the laser beam to the object under test; the optical path folding module 6 includes at least one reflector for folding the laser beam reflected by the adjustable angle reflector 5, the length of the folded optical path is 40-60mm, so as to reduce the size of the sensor; The imaging module includes an aspherical imaging lens 7 and a linear CMOS sensor 8. The linear CMOS sensor 8 is disposed on the image plane of the aspherical imaging lens 7. The aspherical imaging lens 7 receives and images the laser beam reflected from the object being measured. The aspherical imaging lens 7 adopts an aspherical structure to reduce aberrations and improve image quality. The aspherical imaging lens 7 is used to receive and image the laser beam reflected from the object being measured, with a focal length of 20-30mm and an imaging magnification of 0.5-2.0. The linear CMOS sensor 8 is used to receive the imaged light signal and convert it into an electrical signal, with a pixel count of 1024-4096 and a measurement frequency of 3000-10000Hz to meet the requirements of high-speed measurement. The signal processing module is electrically connected to the linear CMOS sensor 8; it is used to process electrical signals and output displacement measurement results with a measurement accuracy of ±0.01-0.05mm.

[0032] The top of the cavity seat 1 is fixed to the rotating end of the rotating platform and is coaxially arranged. When the cavity seat 1 rotates around the axis, since the adjustable angle reflector 5 has an angle with the axis, the optical path folding module 6 forms a circle in space for the trajectory of the point laser, and the diameter of the circle changes with the measurement distance.

[0033] The signal processing module is composed of an FPGA. The signal processing module receives the electrical signal from the linear CMOS sensor 8, converts the analog signal into a digital signal through A / D conversion, and calculates the displacement d of the measured object according to the triangulation formula, d=(x-x0)×M×tan(θ_tri); where x is the position of the light spot on the linear CMOS, x0 is the reference position, M is the imaging magnification, and θ_tri is the triangulation angle.

[0034] The angle adjustment unit 4 includes a backing plate 9 fixed inside the cavity seat 1. An angle adjustment plate 10 is attached to the front end of the backing plate 9, and an adjustable angle reflector 5 is fixed to the front end of the angle adjustment plate 10. The angle adjustment plate 10 has multiple arc-shaped guide grooves 11. Limiting bolts 12 or guide posts 13 are provided inside the arc-shaped guide grooves 11. The limiting bolts 12 are screwed onto the backing plate 9. After the angle of the adjustable angle reflector 5 is manually adjusted, it is fixed by the limiting bolts 12. The guide posts 13 are fixed to the backing plate 9 and connected to an angle adjustment driver. The adjustable angle reflector 5 is achieved through the angle adjustment unit 4. Angle adjustment; the angle adjustment driver is a worm gear manual adjustment mechanism 14, which realizes precise adjustment of the included angle α, with an adjustment resolution of <0.01°; when manually adjusting the angle, loosen the limiting bolt 12 and rotate the arc-shaped guide groove 11 of the angle adjustment plate 10 along the limiting bolt 12. After the angle adjustment is completed, tighten the limiting bolt 12 and the backing plate 9 again to lock the position of the angle adjustment plate 10; after the angle adjustment is completed, or by rotating the knob, drive the worm of the worm gear manual adjustment mechanism 14 to rotate. The worm drives the angle adjustment plate 10 to rotate synchronously through the worm gear, thereby realizing the angle adjustment of the adjustable angle reflector 5.

[0035] The angle adjustment driver includes a rotating shaft fixed at the center of the angle adjustment plate 10; the rotating shaft is rotatably mounted to the backing plate 9 via bearings; the rotating shaft is connected to the drive motor 15 on the backing plate 9 via a transmission mechanism; the transmission mechanism is a transmission mechanism composed of a synchronous pulley and a synchronous belt, or a transmission mechanism composed of a gear transmission box 16; during electric angle adjustment, the drive motor 15 drives the rotating shaft to rotate via the transmission mechanism, the rotating shaft drives the angle adjustment plate 10 to rotate synchronously, thereby synchronously driving the adjustable angle reflector 5 to rotate, so as to change the reflection angle; when the angle adjustment plate 10 rotates, the arc-shaped guide groove 11 of the angle adjustment plate 10 is guided to rotate along the guide post 13.

[0036] This embodiment executes the complete optical path process according to the operating parameters in Table 1. The specific steps are as follows: Step 1, Laser Emission and Beam Modulation: Laser semiconductor 2 emits a laser beam with a power of 5-20mW and a wavelength of 650nm (red laser) or 780nm (infrared laser); the initial divergence angle of the laser beam is 10°-30°, which needs to be modulated by a subsequent optical system; Step 2, beam focusing: Focusing lens 3 receives the laser beam emitted by laser semiconductor 2. Focusing lens 3 is a plano-convex lens or biconvex lens with a focal length f1 of 8-15mm (selected value is 10mm). Focusing lens 3 focuses the diverging laser beam to form a focused spot. The diameter d1 of the focused spot is 0.05-0.2mm (selected value is 0.1mm). The focused spot is located on the focal plane of focusing lens 3. Step 3, Adjustable angle reflector 5 reflection: The focused laser beam illuminates the adjustable angle reflector 5, whose reflective surface is coated with a high-reflectivity film (reflectivity > 95%); the adjustable angle reflector 5 forms an angle α with the axis, the range of which is 5°-20° (preferred value: 15°); the angle of the adjustable angle reflector 5 can be manually adjusted and then fixed (not adjusted in real time); by adjusting the angle α, the variation of the diameter of the circle formed during rotation scanning with the measurement distance can be controlled; Step 4: The optical path folding module 6 uses two reflectors (a first reflector and a second reflector). The first reflector is used to reflect the laser beam after it has been reflected by the adjustable angle reflector 5 to the second reflector. The second reflector is used to reflect the laser beam to the object being measured. Optical path folding (reflection by the first reflecting mirror): The laser beam reflected by the adjustable angle reflecting mirror 5 illuminates the first reflecting mirror. The angle α1 between the reflecting surface of the first reflecting mirror and the optical axis is 30°-60° (preferred value: 45°). The first reflecting mirror reflects the laser beam, realizing the first optical path folding. The optical path folding angle β1 is 60°-120° (preferred value: 90°). Step 5, Optical Path Folding (Reflection by the Second Reflector): The laser beam reflected by the first reflector illuminates the second reflector; the angle α2 between the reflecting surface of the second reflector and the optical axis is 30°-60° (preferred value: 45°); the second reflector reflects the laser beam, achieving a second optical path folding; the optical path folding angle β2 is 60°-120° (preferred value: 90°); after two optical path folds, the total length of the optical path is folded from a straight distance L0 (approximately 80-120mm) to L1 (approximately 40-60mm), reducing the volume by approximately 40%. Step 6, Point Laser Spot Formation and Rotational Scanning Circle: The laser beam reflected by the second reflector finally illuminates the object being measured. Since the laser beam is focused by the focusing lens 3, a point spot is formed on a plane perpendicular to the optical axis. The diameter of the point spot, d, is 0.05-0.2 mm (preferred value: 0.1 mm). Rotational scanning to form a circle: When the entire sensor rotates around the vertical axis, due to the angle α between the adjustable angle reflector 5 and the axis, the trajectory of the point laser in space forms a circle. Relationship between circle diameter and distance: The closer to the sensor, the smaller the circle diameter; the farther from the sensor, the larger the circle diameter. Effective measurement range: 350±250 mm (i.e., 100 mm-600 mm); Near end (100 mm distance): Circle diameter D_near = 35 mm; Far end (400 mm distance): Circle diameter D_far = 100 mm. Relationship between circle diameter and distance: D=D_near+(D_far-D_near)×(L-L_near) / (L_far-L_near); Where D is the diameter of the circle, L is the measurement distance, L_near=100mm, L_far=600mm; by adjusting the included angle α of the adjustable angle reflector 5, the change law of the circle diameter with distance can be controlled, thereby adapting to the measurement needs of different height ranges; Step 7, Reflected light collection: The laser beam reflected from the object being measured (diffuse reflection) enters the imaging module after being reflected by the second mirror, the first mirror, and the adjustable angle mirror 5; the intensity of the reflected light is 1%-10% of the intensity of the incident light (depending on the surface characteristics of the object being measured). Step 8, Aspherical Imaging: The aspherical imaging lens 7 receives the reflected light, with a focal length f2 of 20-30mm (preferred value: 25mm); the aspherical imaging lens 7 images the reflected light onto the image plane of the linear CMOS sensor 8; the imaging magnification M is 0.5-2.0 (preferred value: 1.0); aberrations (spherical aberration, coma, astigmatism) are reduced through the aspherical design, and the RMS wavefront error is <λ / 4 (λ is the laser wavelength); Step 9, photoelectric conversion: The linear CMOS sensor 8 receives the imaged light signal, wherein the number of pixels is 1024-4096 (preferred value: 2048); the pixel size p is 5-14μm (preferred value: 7μm); the measurement frequency f is 3000-10000Hz (preferred value: 5000Hz); the linear CMOS sensor 8 converts the light signal into an electrical signal (analog signal). Step 10, Signal Processing and Displacement Calculation: The signal processing module (FPGA) receives the electrical signal from the linear array CMOS sensor 8, converts the analog signal into a digital signal through A / D conversion, and calculates the displacement of the object under test according to the principle of triangulation: displacement d=(x-x0)×M×tan(θ_tri); where: x is the position of the spot on the linear array CMOS, x0 is the reference position, M is the imaging magnification, θ_tri is the triangulation angle (usually 30°-60°), and the measurement accuracy is ±0.01-0.05mm (preferred value: ±0.01mm).

[0037] Table 1: Operating Parameters Table for Example 1

[0038] The working principle of this embodiment is as follows: 1. The adjustable angle reflector 5 is adjusted as follows: the adjustable angle reflector 5 forms an angle α (5°-20°) with the axis, which can be manually adjusted and then fixed. 2. Rotation scanning forms a circle: When the entire sensor rotates around the vertical axis, due to the angle α between the adjustable angle reflector 5 and the vertical axis, the trajectory of the point laser in space forms a circle; 3. The relationship between the diameter of the circle and the distance: The closer to the sensor, the smaller the diameter of the circle (35mm at the nearest 100mm). The farther away from the sensor, the larger the diameter of the circle (at a distance of 400mm: 100mm). Effective measuring range: 350±250mm (100mm-600mm); 4. By adjusting the included angle α of the adjustable angle reflector 5, the scanning circle diameter can be controlled at different measurement distances. A smaller circle diameter (35mm) is used at the near end (100mm distance), which is suitable for measuring features with smaller heights (such as small welds, thin lines, etc.); a larger circle diameter (100mm) is used at the far end (400mm distance), which is suitable for measuring features with larger heights (such as large welds, thick lines, etc.). Therefore, different height ranges can be used for measurement at different measurement distances, improving measurement flexibility. 5. Application Scenarios: Weld Seam Locator: When measuring at close range, using a small circle diameter (35mm) can more accurately locate small weld seams; when measuring at long distance, using a large circle diameter (100mm) can cover a larger measurement range; through a single rotation scan, measurement data for different height ranges at different distances can be obtained, improving measurement efficiency; 6. Optical path folding: By folding the optical path, the original long straight-line distance of the optical path is folded into a compact structure, which significantly reduces the size of the sensor.

[0039] The laser sensor used in the rotary 3D contour measurement system of this embodiment 1 was subjected to performance testing. The testing method is as follows: I. Spot laser test, the test method is as follows: Test standard: GB / T26111-2010 "Laser Displacement Sensors"; 1.1 Fix the sensor and point the laser beam onto a standard white board (reflectivity > 90%). 1.2 Images of point laser spots were captured using a high-resolution CCD camera (2μm pixel size). 1.3 Analyze the shape of the point laser spot using image processing software: 1.4 Spot diameter d: The diameter of the laser spot at the measurement point (FWHM, full width at half maximum). 1.5 Point Spot Circularity: Measure the roundness of the laser spot at a measurement point (circularity > 0.9). 1.6 Spot stability: The stability of the laser spot position at the measurement point (position drift <0.01mm). 2. Test Results (Example 1): Spot diameter d: 0.1 mm (target value: 0.05-0.2 mm); Spot roundness: 0.92 (target value: >0.9); Spot position stability: ±0.008 mm (target value: <0.01 mm); II. Energy distribution test, the test method is as follows: Test standard: ISO 11146 "Methods of test for laser beam width, divergence angle and beam ratio"; 2.1 Measure the total laser power at the point using a laser power meter (accuracy ±1%); 2.2 Use a beam analyzer (such as Spiricon) to measure the point laser energy distribution; 2.3 Analysis parameters: Peak power density: the maximum power density at the center of the point laser spot; Energy distribution: the energy distribution of the point laser spot (Gaussian distribution); Beam quality factor M²: M² < 1.5 (close to an ideal Gaussian beam); Test results (Example 1): Peak power density: 1273mW / mm² (10mW power, 0.1mm diameter spot); Energy distribution: conforms to Gaussian distribution, peak power density to average power density ratio >2.5; Beam quality factor M²: 1.3 (target value: M² <1.5).

[0040] III. Stability testing, the testing method is as follows: Testing standard: GB / T2423.1-2008 Environmental Testing for Electrical and Electronic Products; 3.1 Temperature stability: Tested every 10℃ within the temperature range of -10℃ to +60℃; the changes in the position and diameter of the laser spot at the measurement point are required to be: position drift <0.05mm, diameter change <10%; 3.2 Time stability: Continuous operation for 24 hours, tested hourly; measuring changes in the position and diameter of the laser spot at the measurement point; requirements: position drift <0.02mm, diameter change <5%; 3.3 Vibration stability: Tested under vibration frequency of 10-2000Hz and acceleration of 2g; the changes in the position and diameter of the laser spot at the measurement point are measured; requirements: position drift <0.1mm, diameter change <10%; Test results (Example 1): Temperature stability: position drift 0.03 mm, width change 6% (target value: <0.05 mm, <10%); Time stability: position drift 0.015 mm, width change 3% (target value: <0.02 mm, <5%); Vibration stability: position drift 0.08 mm, width change 7% (target value: <0.1 mm, <10%).

[0041] IV. Rotational scanning circle diameter test, the test method is as follows: 4.1 Adjust the angle α between the adjustable angle reflector 5 and the axis, from 5° to 20°, and test once every 5°; 4.2 Fix the sensor on the rotating platform and rotate it around the axis; 4.3 Measure the diameter of the circle formed at different measurement distances (100mm, 200mm, 300mm, 400mm); 4.4 Verify the relationship between the diameter of the circle and the distance: the closer the distance, the smaller the circle; the farther the distance, the larger the circle.

[0042] Test results (Example 1, included angle α = 12°): Included angle α: 12° (target value: 5°-20°); Effective measuring range: 100-400mm (target value: 250±150mm); Proximal circle diameter (100mm distance): 35mm (target value: 35mm); Distal circle diameter (400mm distance): 100mm (target value: 100mm); Relationship between circle diameter and distance: D = 35 + 65 × (L - 100) / 300, where D is the circle diameter (mm) and L is the measuring distance (mm).

[0043] V. Measurement accuracy test, the test method is as follows: 5.1 Use a standard displacement stage (accuracy ±0.001mm) as the object being measured; 5.2 The displacement stage moves a known distance (1mm, 5mm, 10mm); 5.3 Sensors measure displacement and compare it with standard values; 5.4 Calculate the measurement error: Error = |Measured value - Standard value|; Test results (Example 1): 1mm displacement measurement error: ±0.008mm (target value: ±0.01mm); 5mm displacement measurement error: ±0.010mm (target value: ±0.01mm); 10mm displacement measurement error: ±0.012mm (target value: ±0.01mm); Average measurement accuracy: ±0.01mm (target value: ±0.01mm).

[0044] The experimental data comparing Example 1 with existing mainstream 3D contour measurement technologies are as follows: Comparison with Option 1: Traditional fixed-path laser displacement sensor, Model: Keyence LK-G30 (typical example); Features: Fixed optical path, fixed scanning range (20mm); Comparison Option 2: Area CMOS 3D Profilometer Model: Gocator 3210 (typical example); Features: Area array CMOS, 3D contour measurement; Comparative Solution 3: This invention (Example 1) features: adjustable angle reflector 5 + optical path folding, and adjustable scanning range (10-50mm).

[0045] Table 2: Experimental Data of Example 1 and Existing Technical Solutions

[0046] As shown in Table 2, the scanning circle diameter in this embodiment is adjustable with distance. Compared to other comparative schemes, this embodiment, through the combination of adjustable angle reflector 5 and optical path folding, is the only one that supports controlling the diameter of the rotating scanning circle with distance by adjusting the reflector angle. The variation pattern of this embodiment is: near-end circle diameter 35mm, far-end circle diameter 100mm, effective measurement range 350±250mm (100mm-600mm). Compared to other comparative schemes, this embodiment has a compact overall size: the volume is greatly reduced; high measurement accuracy: accuracy ±0.01mm, comparable to area array CMOS; and fast measurement speed: measurement frequency 5000Hz, 2.5 times faster than area array CMOS.

[0047] Example 2: The laser sensor for a rotary 3D contour measurement system of the present invention adopts a minimal parameter configuration and is suitable for space-constrained applications. Its technical parameters are as follows: Laser semiconductor 2: power 5mW, wavelength 650nm; Focusing lens 3: focal length 8mm, focused spot diameter 0.05mm; Adjustable angle reflector 5: Angle α = 5° with the vertical axis (minimum angle), fixed after adjustment; Optical path folding structure: It includes only one reflector, and the optical path length after folding is 40mm; Aspherical imaging lens 7: focal length 20mm, magnification 0.5; Linear CMOS sensor 8: 1024 pixels, pixel size 5μm, measurement frequency 3000Hz; Spot diameter: 0.05mm; Effective measuring range: 100-300mm (smaller measuring range); Proximal circle diameter (100mm distance): 25mm; Distant circle diameter (300mm distance): 70mm; Measurement accuracy: ±0.05mm; The differences between this embodiment and Embodiment 1 are as follows: The parameters are minimized to achieve the most compact design; the folded optical path module uses only one reflector; the adjustable-angle reflector 5 has an included angle α = 5° (minimum angle), forming a smaller scanning circle; the effective measurement range is smaller (100-300mm), suitable for close-range measurements, with slightly lower measurement accuracy, but meeting the requirements of compact applications; this embodiment is smaller in size, with a folded optical path length of only 40mm, reducing the volume by approximately 20% compared to Embodiment 1; it has the lowest cost: using a 1024-pixel linear CMOS array, reducing costs by approximately 30%; the scanning circle diameter is smaller: 25mm at the near end and 70mm at the far end, suitable for measuring features with smaller heights; it is suitable for space-constrained compact applications, such as small robot end effectors and precision assembly lines.

[0048] Example 3: The laser sensor for a rotary 3D contour measurement system of the present invention employs maximum parameter configuration and is suitable for high-precision measurement applications; the technical parameters are as follows: Laser Semiconductor 2: Power 20mW, wavelength 780nm (infrared laser, reducing ambient light interference); Focusing lens 3: focal length 15mm, focused spot diameter 0.2mm; Adjustable angle reflector 5: Angle α with the vertical axis = 20° (maximum angle), fixed after adjustment; Optical path folding structure: including a first reflector and a second reflector, the optical path length after folding is 60mm; Aspherical Imaging Lens 7: Focal length 30mm, magnification 2.0; Linear CMOS sensor 8: 4096 pixels, pixel size 14μm, measurement frequency 10000Hz; Spot diameter: 0.2mm; Effective measuring range: 150-500mm (larger measuring range); Proximal circle diameter (150mm distance): 40mm; Distant circle diameter (500mm distance): 150mm; Measurement accuracy: ±0.01mm.

[0049] The differences between this embodiment and Embodiment 1 are as follows: The parameters are set to their maximum values ​​to achieve the highest accuracy and maximum scanning range; the adjustable-angle reflector 5 has an included angle α = 20° (maximum angle), forming a larger scanning circle; infrared laser is used to reduce ambient light interference; a 4096-pixel linear CMOS array improves measurement accuracy; and the measurement frequency is 10000Hz to meet high-speed measurement requirements. The technical effects of this embodiment are as follows: Highest measurement accuracy: ±0.01mm, meeting high-precision measurement requirements; fastest measurement speed: 10000Hz, meeting high-speed measurement requirements; largest scanning circle diameter: 40mm at the near end and 150mm at the far end, adaptable to objects with a wide height range; largest effective measuring range (150-500mm), suitable for long-distance measurement; applicable to: high-precision measurement applications, such as precision machining inspection and scientific research measurement.

[0050] Example 4: The laser sensor for a rotating 3D contour measurement system of the present invention employs different lens combinations and a dual-lens focusing structure. Specifically, the difference between this embodiment and Embodiment 1 is that the focusing lens 3 adopts a dual-lens combination structure, further improving the focusing quality. The technical parameters are as follows: Focusing lens 3: Employs a dual-lens combination (plano-convex lens + biconvex lens); First lens: Plano-convex lens, focal length 12mm; Second lens: Biconvex lens, focal length 8mm; Combined focal length: 10mm (same as in Example 1); The focused spot diameter is 0.08 mm (smaller than 0.1 mm in Example 1), and other parameters are the same as in Example 1. The technical effects of this embodiment are as follows: Higher focusing quality: The combination of dual lenses reduces aberrations and results in a smaller focused spot; smaller spot size: 0.08mm, improving measurement accuracy; suitable for: applications requiring high-precision measurement.

[0051] Example 5: The laser sensor for a rotating 3D contour measurement system of the present invention employs different combinations of reflectors, specifically a three-reflector optical path folding structure. The difference between this embodiment and Embodiment 1 is that the optical path folding structure uses three reflectors, further reducing the volume. Technical parameters are as follows: Optical path folding structure: includes a first reflecting mirror, a second reflecting mirror, and a third reflecting mirror; the first reflecting mirror has an angle of 45°; the second reflecting mirror has an angle of 45°; the third reflecting mirror has an angle of 45°; the length of the folded optical path is 35mm (shorter than 50mm in Example 1); other parameters are the same as in Example 1; the technical effects of this embodiment are as follows: Smaller size: The optical path is only 35mm long after folding, and the volume is reduced by about 30% compared to Example 1; suitable for: ultra-compact applications, such as micro robots and portable measuring devices.

[0052] Example 6: like Figure 7The laser sensor shown for the rotary 3D contour measurement system also includes a coupling error compensation module. This module compensates for the coupling errors of the adjustable angle mirror 5, the optical path of the folded optical path, and the imaging position, performing closed-loop compensation across the entire angle and measurement range. The coupling error model is obtained through pre-calibration, covering coupling error data across the entire adjustment range, measurement range, and operating temperature range of the adjustable angle mirror 5. The coupling error compensation module incorporates coupling error models for angle, optical path, and imaging. An angle sensor is integrated into the rotating end of the angle adjustment unit 4. This angle sensor forms a closed-loop control with the angle adjustment driver, and the angle sensor synchronizes real-time angle data to the coupling error compensation module. The coupling error compensation module is connected to the signal processing module. The inputs of the coupling error model include the real-time angle of the adjustable-angle reflector 5, the measurement distance, and the internal temperature. The outputs are the optical path compensation value, the triangulation reference parameter correction value, and the spot centroid offset compensation value. The coupling error compensation module dynamically compensates the displacement calculation results based on the real-time inputs to solve the coupling errors caused by changes in the angle, changes in the optical path of the folded optical path, and temperature drift, ensuring consistent measurement accuracy across the entire angle range. The coupling error model completes a closed-loop operation of pre-calibration model establishment, real-time input acquisition, dynamic calculation compensation, and result correction output. It works in conjunction with the adjustable-angle reflector 5 and the folded optical path throughout the process. The specific steps are as follows: Model pre-calibration construction: Using a high-precision calibration platform, error data under all operating conditions is acquired, and a precise mapping relationship is established between the included angle α, the measurement distance L, the temperature T, and the compensation value, forming a callable coupled error model. The steps are as follows: Calibration environment setup: Set up a calibration platform including a high-precision laser interferometer, a temperature control chamber, and a precision displacement stage. Fix the laser sensor to ensure a calibration accuracy better than ±0.001mm. The temperature control chamber covers the sensor's operating temperature range of -10℃ to 60℃. Full variable traversal sampling: The adjustable angle reflector 5 is adjusted in the full range of 5°-20° (step ≤ 0.5°), the sensor has a full measurement range of 100mm-400mm (step ≤ 5mm), and the full temperature range of -10℃ to 60℃ (step ≤ 5℃). Three-dimensional variable combination traversal is performed. For each group (α, L, T), the original displacement measurement value of the sensor and the standard value of the laser interferometer are collected. Error Calculation and Fitting: For each group (α,L,T), the deviation between the original measured value and the standard value is calculated, specifically including four types of sub-errors: optical path error, triangulation reference parameter error, spot centroid offset error, and temperature-coordinated drift error. A multivariate nonlinear fitting algorithm (such as Gaussian fitting or BP neural network) is used to fit all sub-error data, establish the mapping relationship between input quantities (α,L,T) and output quantities (optical path compensation value, reference parameter correction value, centroid offset compensation value, and temperature drift compensation value), form a coupling error model, and solidify it into the coupling error compensation module of the sensor. Model validation and optimization: Randomly select multiple sets of (α,L,T) combinations of non-sampling points for validation. If the accuracy fluctuation after compensation is > ±0.01mm, re-optimize the fitting algorithm and model parameters until the accuracy requirements of the whole working condition are met. Real-time compensation for actual measurements: During sensor operation, the coupling error compensation module collects various input data in real time, calls the pre-calibrated model to calculate compensation values, and dynamically corrects the original displacement data. The steps are as follows: Real-time data acquisition: Three sets of data inputs are acquired synchronously, and the acquisition frequency matches the sensor measurement frequency (3000~20000Hz): Angle α: provided by an angle sensor, with a detection accuracy of <0.005°; Measurement distance L: the original displacement measurement value calculated by the signal processing and linkage control module; Temperature T: real-time temperature acquired by the distributed temperature transmitter inside cavity 1. Model calling and compensation value calculation: The coupling error compensation module inputs the real-time collected (α,L,T) into the pre-calibrated coupling error model, and the model automatically calculates and outputs four types of compensation values: optical path compensation value, triangulation reference parameter correction value, spot centroid offset compensation value, and temperature drift co-compensation value. Dynamic correction of raw data: The signal processing module will calculate four types of compensation values ​​and correct the optical path parameters, triangulation reference, CMOS spot centroid coordinates, and temperature drift deviation in the original displacement calculation process, respectively, to complete the coordinated compensation of errors; Accurate result output: After correction, the final high-precision displacement measurement value is obtained, which can be directly output or used for the generation of 3D contour data for linkage scanning; at the same time, the compensation data is transmitted back to the model in real time, providing data support for subsequent model iteration and optimization; the model data covers the entire range of adjustable angle, measurement range, and operating temperature, with no compensation blind spots; the calculation and compensation processes are all hardware-level fast calculations, with a synchronization error of <1μs, which does not affect the normal measurement of the sensor; the sensor supports automatic full-angle self-calibration, during which new error data will be collected and the model parameters will be automatically updated to offset the model errors caused by the aging of the device and structural drift due to long-term use.

[0053] Example 7: like Figure 8The laser sensor shown for a rotating 3D contour measurement system further includes a transmit / receive common path matching module. This module includes a polarization beam splitting unit and an optical axis tracking calibration unit. The polarization beam splitting unit comprises a polarization beam splitting prism and a quarter-wave plate. The polarization beam splitting prism is positioned between the laser emission module and the angle-adjustable execution module, and the quarter-wave plate is positioned between the polarization beam splitting prism and the angle-adjustable execution module. A set of beam constraint adaptation units is fixed at both the beginning and end of the optical path folding module 6. Each beam constraint adaptation unit consists of an aperture and a beam constraint adaptation unit. The beam first passes through the aperture, then the polarization beam splitting prism, and finally enters the optical path folding module 6. The aperture's aperture matches the beam diameter within the full adjustment range of the α angle (0.1-0.2 mm larger than the maximum beam diameter), filtering stray light from the beam edge to ensure the main beam propagation direction is unique. The transmit / receive common path matching module uses a polarization beam splitting prism and a quarter-wave plate in conjunction, and adjusts their spatial position relative to the adjustable angle reflector 5 for calibration. The process is as follows: Linearly polarized light output from the laser emitting module is converted into circularly polarized light by a polarizing beam splitter and a quarter-wave plate before being incident on an adjustable-angle reflector 5, with the incident optical axis strictly coinciding with the adjustment and rotation center of the adjustable-angle reflector 5. The diffusely reflected light from the object being measured is reflected by the adjustable-angle reflector 5 and returns along the original incident light path, being converted into vertically polarized light again by the quarter-wave plate and precisely reflected by the polarizing beam splitter to the imaging module. This ensures that the emitting and receiving optical axes remain coaxial at all times, unaffected by the adjustable angle. The adjustment of the α angle (5°-20°) of the reflector 5 has an impact; among them, the reflectors of the optical path folding module 6 adopt a precise track-fixed arrangement, and the fixed reflector is adapted to the full-angle beam. All the reflectors of the optical path folding module 6 are fixed on the cavity base 1. Before fixing, the optical path trajectory is pre-planned, the spatial angle of the reflector is accurately calibrated, and an effective light-transmitting surface redundancy arrangement is made so that the fixed reflector can fully receive all the beams of the adjustable angle reflector 5 within the adjustment range of 5°-20°, without truncation or offset. The specific arrangement is as follows: Z-type folded optical path trajectory pre-planning: Based on the light output angle range of 5°-20° of the α angle of the adjustable angle reflector 5, a unique fixed folded optical path trajectory is pre-planned through optical simulation (such as Zemax). The optimal spatial installation angle (error ≤ ±0.001°) and spacing of each reflector are determined to ensure that the α angle is within the full adjustment range, and that the emitted / received beams can be directed at each fixed reflector at a fixed incident angle, and that the optical axis trajectory after reflection is unique and without offset. Redundant arrangement of effective light transmission surfaces of reflectors: Each reflector covers the beam illumination area within the full adjustment range of the α angle, preventing the beam from exceeding the light transmission surface of the reflector due to changes in the α angle. At the same time, the reflectors use a fused silica substrate + a high-reflectivity dielectric film (reflectivity >99%) to ensure beam reflection efficiency. Optical axis pre-calibration unit: Offline one-time calibration, solidifying full-angle optical axis compensation parameters. During the laser sensor production stage, full-angle optical axis parameter calibration is completed and solidified into the signal processing module, enabling algorithmic compensation for minute optical axis deviations in a fixed folded optical path. Specific design details: Calibration equipment: A laser collimator (collimation <0.001mm / m) + a high-precision angle stage is used, which is assembled with the sensor on the same optical platform; Full-angle calibration: Adjust the adjustable angle reflector 5 from 5° to 20° in 0.5° increments. At each α angle, use a laser collimator to detect the coaxiality deviation of the output / receive optical axis of the folded optical path, record the deviation data, and convert it into optical axis compensation parameters. Parameter solidification: All optical axis compensation parameters corresponding to the α angle are solidified into the signal processing module. When the sensor is working, it automatically calls the corresponding compensation parameters according to the real-time α angle of the closed-loop angle detection unit. The CMOS photosensitive area of ​​the adaptive imaging module is finely adjusted through the algorithm to achieve accurate compensation of optical axis deviation and ensure that the receiving field of view and the transmitting field of view are always aligned.

[0054] Beam constraint adapter unit: A set of miniature beam constraint adapter units is set at the beginning and end of the optical path folding module 6. The lens parameters are optimized through optical simulation to ensure that the α angle is within the full adjustment range. The emitted / received beams remain collimated after passing through the lens (beam divergence angle <0.01mrad), and the collimated optical axis strictly coincides with the folded optical path trajectory to avoid field of view shift caused by beam divergence.

[0055] The workflow of the transmit / receive common path matching module is as follows: Emitter: After passing through the polarization beam splitter, the laser beam is incident on the rotation center of the adjustable angle reflector 5. When the α angle is adjusted, the emitted optical axis only undergoes a fixed center deflection. After passing through the optical path folding module 6, the beam propagates along a pre-planned fixed trajectory and is kept collimated by the beam constraint adapter unit. The direction of the emitted field of view corresponds precisely to the α angle without any offset. Receiver: The diffuse reflected light from the object under test returns along the original path of the emitted optical axis, and returns to the polarization beam splitter unit through the optical path folding module 6. Due to the pre-coaxial arrangement of the polarization beam splitter unit, the receiving optical axis and the emitted optical axis are completely coincident. Algorithm compensation: The signal processing module calls the pre-fixed optical axis compensation parameters based on the real-time α angle, fine-tunes the CMOS photosensitive area, and compensates for the small optical axis deviation of the optical path folding module 6. Finally, the adjustable angle reflector 5 achieves 100% accurate matching between the transmitting field of view and the receiving field of view within the full adjustment range of 5°-20°.

[0056] Example 8: like Figure 9The laser sensor shown is used in a rotary 3D contour measurement system. The signal processing module integrates a rotation-linked scanning control module, which is hardware-synchronized with the angle encoder of the rotating platform. The synchronization error is <1μs. It supports two scanning modes: fixed-angle rotation scanning mode and dynamic linkage variable-diameter scanning mode, as detailed below: Fixed-angle rotation scanning mode: The included angle α of the adjustable-angle reflector 5 is locked, and the sensor rotates to form a circular scanning trajectory that changes linearly with the measurement distance. Dynamic linkage variable diameter scanning mode: During the rotation of the sensor, the included angle α of the adjustable angle reflector 5 is adjusted in real time according to the rotation angle to realize variable diameter scanning, spiral scanning, directional fan-shaped scanning, and irregular contour following scanning. During the dynamic adjustment of the α angle, the transmit and receive common path matching module always ensures the matching of the transmit and receive fields of view.

[0057] The above embodiments are merely preferred embodiments of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention are included within the scope of the present invention.

Claims

1. A laser sensor for a rotary 3D contour measurement system, characterized in that: Includes a cavity seat, and a detection module is fixed inside the cavity seat. The detection module includes: A laser emitting module, comprising a laser semiconductor and a focusing lens, wherein the focusing lens is disposed on the light emission path of the laser semiconductor; Angle-adjusting module, comprising an angle-adjusting unit, wherein an adjustable angle reflector is fixed at the angle-adjusting end of the angle-adjusting unit, the adjustable angle reflector is disposed on the light output path of the focusing lens, and the angle between the adjustable angle reflector and the axis of the cavity seat is adjustable from 5° to 20°. An optical path folding module is disposed on the light output path of an adjustable angle reflector; the optical path folding module reflects the laser beam to the object under test; An imaging module, comprising an aspherical imaging lens and a linear CMOS sensor, wherein the linear CMOS sensor is disposed on the image plane of the aspherical imaging lens; the aspherical imaging lens receives and images a laser beam reflected from the object under test. A signal processing module, which is electrically connected to a linear CMOS sensor.

2. The laser sensor for a rotary 3D contour measurement system according to claim 1, characterized in that: The top of the cavity seat is fixed and coaxially arranged with the rotating end of the rotating platform; when the cavity seat rotates around the axis, due to the angle between the adjustable angle reflector and the axis, the optical path folding module forms a circle in space for the trajectory of the point laser, and the diameter of the circle changes with the measurement distance.

3. The laser sensor for a rotary 3D contour measurement system according to claim 1, characterized in that: The signal processing module is composed of an FPGA. The signal processing module receives the electrical signal from the linear CMOS sensor, converts the analog signal into a digital signal through A / D conversion, and calculates the displacement d of the measured object according to the triangulation formula, d=(x-x0)×M×tan(θ_tri); where x is the position of the light spot on the linear CMOS, x0 is the reference position, M is the imaging magnification, and θ_tri is the triangulation angle.

4. The laser sensor for a rotating 3D contour measurement system according to claim 1, characterized in that: The angle adjustment unit includes a backing plate fixed to the inner side of the cavity seat, an angle adjustment plate attached to the front end of the backing plate, and an adjustable angle reflector fixed to the front end of the angle adjustment plate. The angle adjustment plate has multiple arc-shaped guide grooves, and limit bolts or guide posts are provided inside the arc-shaped guide grooves. The limit bolts are screwed to the backing plate. After the angle of the adjustable angle reflector is manually adjusted, it is fixed by the limit bolts. The guide posts are fixed to the backing plate and connected to an angle adjustment driver. The angle adjustment driver is a worm gear manual adjustment mechanism.

5. The laser sensor for a rotating 3D contour measurement system according to claim 4, characterized in that: The angle adjustment driver includes a rotating shaft fixed at the center of the angle adjustment plate; the rotating shaft is rotatably mounted to the back plate via bearings; the rotating shaft is connected to a drive motor on the back plate via a transmission mechanism; the transmission mechanism is a transmission mechanism consisting of a synchronous pulley and a synchronous belt, or a transmission mechanism consisting of a gear transmission box.

6. The laser sensor for a rotating 3D contour measurement system according to claim 1, characterized in that: The optical path folding module includes one or more fixed reflectors; the optical path folding module is a common optical path structure for receiving and transmitting; the laser beam emitted by the laser emission module is reflected by the adjustable angle reflector, enters the optical path folding module to complete optical folding, and is reflected to the object under test. The received beam reflected by the object under test returns along the original folded optical path.

7. The laser sensor for a rotating 3D contour measurement system according to claim 4, characterized in that: It also includes a coupling error compensation module, which has a built-in coupling error model for angle, optical path, and imaging; the rotating end of the angle adjustment unit integrates an angle sensor, which forms a closed-loop control with the angle adjustment driver, and the angle sensor synchronizes real-time angle data to the coupling error compensation module; the coupling error compensation module is connected to the signal processing module, and the inputs of the coupling error model include the real-time included angle of the adjustable angle reflector, the measurement distance, and the internal temperature, and the outputs are optical path compensation value, triangulation reference parameter correction value, and spot centroid offset compensation value; The coupling error compensation module dynamically compensates the displacement calculation results based on the real-time input, eliminating coupling errors caused by changes in the included angle, changes in the optical path of the folded optical path, and temperature drift.

8. The laser sensor for a rotating 3D contour measurement system according to claim 7, characterized in that: It also includes a transmit / receive common path matching module, which includes a polarization beam splitting unit and an optical axis follower calibration unit; the polarization beam splitting unit includes a polarization beam splitting prism and a quarter-wave plate, the polarization beam splitting prism is disposed between the laser emission module and the angle-adjustable execution module, and the quarter-wave plate is disposed between the polarization beam splitting prism and the angle-adjustable execution module; a set of beam constraint adaptation units is fixed at both the beginning and end of the optical path folding module, and the beam constraint adaptation unit is composed of an aperture and a beam constraint adaptation unit.

9. The laser sensor for a rotary 3D contour measurement system according to claim 1, characterized in that: The optical path folding module is a Z-type multi-level folded optical path, an M-type multi-level folded optical path, or a U-type folded optical path.

10. The laser sensor for a rotary 3D contour measurement system according to claim 2, characterized in that: The signal processing module has a built-in rotation linkage scanning control module, which is hardware synchronized with the angle encoder of the rotating platform. The rotation linkage scanning control module includes fixed angle rotation scanning and dynamic linkage variable diameter scanning.

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