Grating interference measuring device and method based on large-size light spots

Abstract

The invention relates to the technical field of optical measurement, in particular to a grating interference measuring device and method based on large-size light spots. The device comprises a light source module which adopts a laser light source with high stability, and the laser light source comprises a wavelength locking device; the collimation and beam expansion module is connected with the light source module; the light splitting module adopts a combined structure of a polarization splitting prism and a lambda / 4 wave plate; the reference grating module comprises a reference grating and a three-dimensional precision adjustment platform; the measuring grating module comprises a measuring grating and a self-adaptive height adjusting mechanism; the imaging module comprises a large-view-field telecentric imaging lens group and a high-speed CMOS image sensor; and a data processing module. One-time measurement of the surface of a large-area object is achieved through the collimation and beam expanding module, efficiency is improved, local interference errors are reduced, the stable laser light source and the reasonable design module are adopted, environmental influences are reduced, optical design is optimized, aberration is reduced, automatic and intelligent measurement is achieved, and convenience and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the field of optical measurement technology, and in particular to a grating interference measurement device and method based on a large-size light spot. Background Art

[0002] With the advantages of high precision and non-contact, grating interference measurement technology has been widely used in the fields of surface topography measurement, displacement measurement, etc. In the measurement process of traditional grating interference measurement devices, the used light spot size is small, which has obvious defects when measuring the surfaces of large-area and complex-shaped objects. First, the small light spot needs to perform point-by-point scanning measurement on the object surface, and the measurement efficiency is extremely low, making it difficult to meet the requirements of rapid detection. Second, when measuring with a small light spot, it is easily affected by factors such as local defects and dust on the object surface, resulting in a decrease in the accuracy and reliability of the measurement results. Third, for some objects with macroscopic surface features and microscopic topography changes, the small light spot cannot simultaneously obtain comprehensive surface information, which limits the comprehensive analysis and evaluation of the object surface.

[0003] To solve the above problems, some studies have tried to increase the light spot size, but new problems have emerged during the process of increasing the light spot size. Due to the increase in the light spot size, the light beam is more easily affected by environmental factors (such as air disturbance, temperature change, etc.) during propagation, resulting in unstable interference fringes, which in turn affects the measurement accuracy. At the same time, the distribution of the large-size light spot on the grating is uneven, which will generate large aberrations, causing the interference fringes to be distorted, further reducing the accuracy of the measurement results. Therefore, the present application proposes a device and method that can effectively utilize a large-size light spot for stable and high-precision grating interference measurement. Summary of the Invention

[0004] The object of the present invention is to propose a device and method that can effectively utilize a large-size light spot for stable and high-precision grating interference measurement in view of the problems existing in the background art.

[0005] On the one hand, the present invention provides a grating interference measurement device based on a large-size light spot, including:

[0006] A light source module, which uses a laser light source with high stability. The laser light source includes a wavelength locking device for stabilizing the output wavelength within the range of 632.8 nm ± 0.1 nm;

[0007] A collimating and beam expanding module, connected to the light source module, including an aspherical collimating lens, a beam shaper, and multiple groups of beam expanding lens groups arranged in sequence along the optical path. The beam shaper is used to convert the Gaussian beam into a flat-top beam, and the beam expanding lens groups adopt a telecentric optical design to expand the beam into a large-size parallel beam with a diameter of 50 - 100 mm, and the wavefront error is less than λ / 10;

[0008] The beam splitting module adopts a combined structure of a polarization beam splitting prism and a λ / 4 wave plate, and is used to split a large-size parallel beam into a reference beam and a measurement beam with an adjustable intensity ratio, and the intensity ratio is dynamically adjusted within the range of 30:70 - 70:30;

[0009] The reference grating module includes a reference grating and a three-dimensional precision adjustment platform; the reference grating is a transmissive blazed grating with a grating pitch of 1.5 - 3μm, and an antireflection film is coated on the grating surface. The three-dimensional precision adjustment platform can achieve an angular adjustment accuracy of ±0.1° and a displacement adjustment accuracy of ±1μm;

[0010] The measurement grating module includes a measurement grating and an adaptive height adjustment mechanism. The measurement grating has the same optical parameters as the reference grating, and the adaptive height adjustment mechanism is used to automatically adjust the distance between the measurement grating and the object surface to the optimal measurement position according to the surface topography of the object to be measured;

[0011] The imaging module includes a large field-of-view telecentric imaging lens group and a high-speed CMOS image sensor. The imaging lens group adopts an apochromatic design, covers a measurement field of view of 50mm × 50mm, the frame rate of the image sensor is ≥100fps, and the pixel size is ≤5μm;

[0012] The data processing module adopts a parallel computing architecture, including a GPU acceleration unit and an FPGA preprocessing unit. The data processing module is built-in with a phase unwrapping algorithm, a sub-pixel positioning algorithm, and a noise suppression filter to complete the processing and analysis of a single-frame interference image.

[0013] Optionally, the beam shaper in the collimating and beam expanding module adopts a microlens array structure. The microlens array consists of thousands of microlens units with a diameter of 50 - 100μm, and is used to convert a Gaussian-distributed laser beam into a flat-top beam with a uniform intensity distribution.

[0014] Optionally, the beam splitting module further includes an optical intensity monitoring unit. The optical intensity monitoring unit monitors the optical intensities of the reference beam and the measurement beam in real time, and feeds back to the control system to dynamically adjust the rotation angle of the λ / 4 wave plate to keep the intensity ratio of the two beams stable within the range of ±2% of the set value.

[0015] Optionally, the three-dimensional precision adjustment platform of the reference grating module includes a piezoelectric ceramic actuator and a flexible hinge structure. The displacement resolution of the piezoelectric ceramic actuator reaches 0.1nm, and the flexible hinge structure is used to reduce the influence of mechanical vibration on the grating position.

[0016] Optionally, the adaptive height adjustment mechanism of the measurement grating module includes a laser ranging sensor and a closed-loop control system. The laser ranging sensor measures the distance between the surface of the object to be measured and the measurement grating in real time. The closed-loop control system drives a stepper motor to adjust the position of the measurement grating according to the measurement result, and the adjustment accuracy is ±5μm.

[0017] Optionally, the diffractive optical element is used to correct high-order aberrations that cannot be eliminated by traditional refractive lenses, so that the spatial resolution in the entire measurement field of view is better than 5μm.

[0018] Optionally, the noise suppression filter of the data processing module adopts a composite filtering algorithm combining wavelet transform and Kalman filtering, which is used to suppress the influence of environmental vibration, air turbulence and circuit noise on the interference fringes.

[0019] On the other hand, the present invention also proposes a measurement method based on grating interference with a large-size light spot using the above device, including the following steps:

[0020] Step 1: Initialize the system and set measurement parameters, including light spot size, light intensity ratio, and sampling frequency;

[0021] Step 2: The light source module emits a stable laser beam, which forms a large-size flat-top parallel beam through the collimating and beam expanding module;

[0022] Step 3: The beam splitting module divides the large-size parallel beam into a reference beam and a measurement beam, and optimizes the intensity ratio of the two beams by adjusting the angle of the λ / 4 wave plate;

[0023] Step 4: The reference beam irradiates the reference grating, and the measurement beam irradiates the measurement grating and reflects off the surface of the object to be measured, respectively generating reference interference fringes and measurement interference fringes;

[0024] Step 5: The imaging module collects the interference fringe image and transmits it to the data processing module;

[0025] Step 6: The data processing module preprocesses the interference fringe image, including denoising, enhancement and positioning;

[0026] Use the Fourier transform phase extraction algorithm to calculate the phase distribution of the interference fringes;

[0027] Use the phase unwrapping algorithm to eliminate the 2π phase ambiguity and obtain a continuous phase map;

[0028] According to the phase-height mapping relationship, calculate the three-dimensional topography information of the surface of the object to be measured;

[0029] Apply the least squares fitting algorithm to optimize the measurement result and improve the measurement accuracy.

[0030] Optionally, the phase unwrapping algorithm adopts a quality-guided path tracking method, combines a confidence map and a reliability ranking strategy, and preferentially unwraps high-quality phase regions to ensure stable propagation during the phase unwrapping process.

[0031] Optionally, it further includes a dynamic compensation step. During the measurement process, the changes in environmental temperature, humidity, and air pressure are monitored in real time, and the measurement results are corrected in real time using a pre-established environmental parameter-phase error compensation model to eliminate the influence of environmental factors on the measurement accuracy.

[0032] Compared with the prior art, the present invention has the following beneficial technical effects:

[0033] By providing a collimating and beam expanding module to expand the light beam emitted by the light source into a large-size parallel light beam, the present invention can achieve a one-time measurement of the surface of a large-area object, greatly improving the measurement efficiency; at the same time, the large-size light spot can cover more surface information, reducing measurement errors caused by local interference factors and improving the accuracy and reliability of the measurement results.

[0034] The present invention adopts a laser light source with high stability and a reasonably designed beam splitting module, reference grating module, and measurement grating module, which can effectively reduce the influence of environmental factors on the interference fringes and ensure the stability of the interference fringes. At the same time, by optimizing the optical design of the collimating and beam expanding module and the imaging module, the aberration can be reduced, making the interference fringes clearer and more accurate, and further improving the measurement accuracy.

[0035] The data processing module of the present invention adopts advanced phase extraction algorithms and fitting algorithms, which can quickly and accurately extract phase information from the interference fringe image and calculate the measurement results, realizing the automation and intelligence of the measurement process and improving the convenience and efficiency of the measurement.

[0036] In summary, the present invention realizes a one-time measurement of the surface of a large-area object through the collimating and beam expanding module, improves the efficiency, reduces local interference errors, and enhances the accuracy. By using a stable laser light source and reasonably designed modules, it reduces the environmental impact, optimizes the optical design to reduce aberration, and improves the measurement accuracy. The data processing module uses advanced algorithms to achieve automated and intelligent measurement, enhancing the convenience and efficiency. Brief Description of the Drawings

[0037] Figure 1 A schematic diagram of the composition of the grating interference measurement device based on a large-size light spot of the present invention is given. Detailed Embodiments

[0038] The technical solutions of the present disclosure will be described clearly and completely below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present disclosure.

[0039] The components of the embodiments of the present disclosure that are typically depicted and shown in the accompanying drawings herein can be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the claimed present disclosure, but merely represents selected embodiments of the present disclosure.

[0040] Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present disclosure.

[0041] Embodiment 1

[0042] As Figure 1 shown, the present invention constructs a complete grating interference measurement device based on large-sized light spots, and the specific configurations of each module are as follows:

[0043] Light source module

[0044] A helium-neon laser with the model number MellesGriot05-LHR-156-00 is selected as the laser light source, and its output power is 1 mW. To ensure wavelength stability, a wavelength locking device is configured. Based on the feedback control principle, the wavelength locking device internally has a wavelength sensor to continuously monitor the laser wavelength. When it detects that the wavelength deviates from 632.8 nm, the temperature controller inside the laser is adjusted through the control circuit to stabilize the wavelength within the range of 632.8 nm ± 0.1 nm.

[0045] Collimation and beam expansion module

[0046] An aspherical collimating lens, a microlens array beam shaper, and two groups of beam expansion lens groups are sequentially installed along the optical path. The aspherical collimating lens is a lens with the model number AC254-050-A-ML produced by Thorlabs, and its focal length is 50 mm, which can effectively collimate the divergent beam emitted by the laser light source. The beam shaper consists of a microlens array composed of 4096 microlens units with a diameter of 80 μm, which can convert a Gaussian beam into a flat-top beam. After testing, the beam intensity uniformity after conversion reaches 97%. Both groups of beam expansion lens groups adopt a telecentric optical design. The first group of beam expansion lens group consists of a convex lens with a focal length of 25 mm and a concave lens with a focal length of 100 mm, and the second group of beam expansion lens group consists of a convex lens with a focal length of 50 mm and a concave lens with a focal length of 200 mm. Finally, the beam is expanded to a diameter of 80 mm, and the wavefront error is detected by an interferometer to be λ / 12 (λ = 632.8 nm).

[0047] Beam splitting module

[0048] The PBS101-13 polarization beam splitter prism of Thorlabs and the WPQ10M-13 λ / 4 waveplate are used in combination. The beam splitting module also integrates two photodetectors of model DET10A-Si as the light intensity monitoring units, which respectively and real-time monitor the light intensities of the reference beam and the measurement beam. The control system uses a microcontroller based on STM32. When the light intensity monitoring unit detects that the intensity ratio of the two beams deviates from the preset value (initially set to 50:50 in this embodiment), it drives the stepper motor to precisely adjust the rotation angle of the λ / 4 waveplate to make the intensity ratio stable within the range of 50:50 ± 2%.

[0049] Reference grating module

[0050] The reference grating selects a transmissive blazed grating produced by Edmund Optics. The grating pitch is 2 μm, and the grating surface is coated with an antireflection film for a wavelength of 632.8 nm, with a light transmittance of 98.5%. The three-dimensional precision adjustment platform consists of three piezoelectric ceramic actuators of model P-726.1CD and a flexure hinge structure. The displacement resolution of the piezoelectric ceramic actuator is 0.1 nm, and it can achieve a displacement adjustment of ±1 μm; through the coordinated operation of the three piezoelectric ceramic actuators and in cooperation with the flexure hinge structure, it can achieve an angular adjustment accuracy of ±0.1°, ensuring that the reference grating is in the best working position.

[0051] Measurement grating module

[0052] The measurement grating has the same optical parameters as the reference grating. The adaptive height adjustment mechanism includes a laser ranging sensor of model LJ-V7000 series, whose measurement accuracy is ±1 μm, and it real-time measures the distance between the surface of the object to be measured and the measurement grating. The closed-loop control system uses a PID control algorithm. According to the difference between the measurement result of the laser ranging sensor and the preset optimal measurement distance, it drives the stepper motor of model NEMA17 to adjust the position of the measurement grating, with an adjustment accuracy of ±5 μm.

[0053] Imaging module

[0054] The large field-of-view telecentric imaging lens group consists of 5 groups of aspherical lenses and 2 groups of diffractive optical elements, and adopts an apochromatic design, which can cover a measurement field of view of 50 mm × 50 mm. A high-speed CMOS image sensor of model acA2500-14gm produced by Basler is selected, with a frame rate of 140 fps and a pixel size of 3.45 μm, which can quickly and clearly collect interference fringe images. After actual testing, the spatial resolution within the entire measurement field of view reaches 4 μm.

[0055] Data processing module

[0056] The NVIDIA Jetson AGX Xavier development board is used as the computing platform, integrating a GPU acceleration unit and an FPGA preprocessing unit. The phase unwrapping algorithm built into the data processing module uses the quality-guided path tracking method. By calculating the local gradient and phase change rate of the interference fringe image, a confidence map is generated, and the pixels are ranked according to their reliability. The high-quality phase regions are preferentially unwrapped. The sub-pixel positioning algorithm uses the sub-pixel positioning method based on gray moments, and the positioning accuracy of 0.1 pixel can be achieved. The noise suppression filter uses a composite filtering algorithm combining wavelet transform and Kalman filter. First, the interference fringe image is decomposed into 3 layers using Daubechies wavelet to remove high-frequency noise. Then, the Kalman filter is used to process the low-frequency signal to suppress the noise caused by environmental vibration, air turbulence, etc.

[0057] A grating interference measurement method based on a large-size light spot using the above device. Taking the measurement of an optical glass flat plate with a size of 40mm×40mm and a surface roughness requirement of Ra0.6μm as an example, the specific measurement steps are as follows:

[0058] Step 1: Initialize the system

[0059] Turn on the power of the measurement device and set the measurement parameters through the host computer software; the light spot size is set to a diameter of 80mm, the initial light intensity ratio is set to 50:50, and the sampling frequency is set to 120Hz; at the same time, preheat the measurement device for 30 minutes and calibrate it using a standard plane mirror to ensure that each module works properly;

[0060] Step 2: Form a large-size flat-top parallel light beam

[0061] The light source module emits a stable laser beam with a wavelength of 632.8nm, which passes through the aspherical collimating lens, the microlens array beam shaper, and two groups of beam expanding lens groups of the collimating and beam expanding module in sequence, and finally forms a large-size flat-top parallel light beam with a diameter of 80mm;

[0062] Step 3: Beam splitting and intensity ratio optimization

[0063] The large-size parallel light beam enters the beam splitting module and is divided into a reference beam and a measurement beam by the polarization beam splitting prism and λ / 4 wave plate combination structure; the light intensity monitoring unit monitors the light intensities of the two beams in real time, and the control system adjusts the rotation angle of the λ / 4 wave plate according to the monitoring results to stabilize the intensity ratio of the two beams within the range of 50:50±2%;

[0064] Step 4: Generate interference fringes

[0065] The reference beam irradiates on the reference grating and generates reference interference fringes after modulation; the measurement beam irradiates on the measurement grating, is modulated and then shoots towards the surface of the optical glass flat plate, and generates measurement interference fringes after reflection;

[0066] Step Five: Image Acquisition

[0067] The large field-of-view telecentric imaging lens group of the imaging module images the reference interference fringes and the measurement interference fringes on the high-speed CMOS image sensor. The image sensor acquires the interference fringe images at a sampling frequency of 120 Hz and transmits the image data to the data processing module through Gigabit Ethernet;

[0068] Step Six: Data Processing and Result Calculation

[0069] Image Preprocessing: After receiving the image data, the data processing module first performs denoising processing on the interference fringe images using a composite filtering algorithm that combines wavelet transform and Kalman filtering, then enhances the image contrast through histogram equalization, and finally locates the interference fringes using the Canny edge detection algorithm;

[0070] Phase Extraction: Using the Fourier transform phase extraction algorithm, a two-dimensional Fourier transform is performed on the preprocessed interference fringe images to extract the phase distribution information of the interference fringes;

[0071] Phase Unwrapping: The quality-guided path tracking method is used to perform unwrapping processing on the extracted phase information. Combining the confidence map and the reliability ranking strategy, the high-quality phase regions are preferentially unwrapped to eliminate the 2π phase ambiguity and obtain a continuous phase map;

[0072] Topography Calculation: According to the phase-height mapping relationship calibrated in advance through a standard step sample block, the continuous phase map is converted into three-dimensional topography information on the surface of the optical glass plate, and the height values of each point are calculated;

[0073] Result Optimization: The least squares fitting algorithm is applied to optimize the calculated three-dimensional topography data, remove the abnormal points, and smooth the data curve. Finally, a high-precision three-dimensional topography measurement result of the surface of the optical glass plate is obtained; after calculation, the actual measured roughness of the surface of the optical glass plate is Ra 0.62 μm, meeting the measurement accuracy requirements;

[0074] During the entire measurement process, the changes in ambient temperature, humidity, and air pressure are monitored in real time; the ambient temperature fluctuates within the range of 22°C ± 1°C, the relative humidity is maintained at 45% ± 5%, and the air pressure is stable at 101.3 kPa ± 0.5 kPa; using the pre-established environmental parameter-phase error compensation model, the measurement results are corrected in real time to effectively eliminate the influence of environmental factors on the measurement accuracy and ensure the accuracy and reliability of the measurement results.

[0075] The above specific embodiments are merely several alternative embodiments of the present invention. Based on the technical solution of the present invention and the relevant revelations of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A grating interference measurement device based on a large-sized light spot, characterized in that Comprising: A light source module, using a laser light source, the laser light source including a wavelength locking device for stabilizing the output wavelength within the range of 632.8nm ± 0.1nm; A collimating and beam expanding module, connected to the light source module, including an aspherical collimating lens, a beam shaper, and multiple groups of beam expanding lens groups arranged in sequence along the optical path. The beam shaper is used to convert a Gaussian beam into a flat-top beam, and the beam expanding lens groups adopt a telecentric optical design to expand the beam into a large-size parallel beam with a diameter of 50 - 100mm, and the wavefront error is less than λ / 10; A beam splitting module, adopting a polarization beam splitting prism and λ / 4 wave plate combination structure, for splitting the large-size parallel beam into a reference beam and a measurement beam with adjustable intensity ratio, and the intensity ratio is dynamically adjusted within the range of 30:70 - 70:30; A reference grating module, including a reference grating and a three-dimensional precision adjustment platform; the reference grating is a transmissive blazed grating with a grating pitch of 1.5 - 3μm, and the grating surface is coated with an antireflection film; A measurement grating module, including a measurement grating and an adaptive height adjustment mechanism. The measurement grating has the same optical parameters as the reference grating, and the adaptive height adjustment mechanism is used to automatically adjust the distance between the measurement grating and the object surface to the optimal measurement position according to the surface topography of the object to be measured; An imaging module, including a large field of view telecentric imaging lens group and a high-speed CMOS image sensor. The imaging lens group adopts an apochromatic design, covering a measurement field of view of 50mm × 50mm, the frame rate of the image sensor is ≥ 100fps, and the pixel size is ≤ 5μm; A data processing module, adopting a parallel computing architecture, including a GPU acceleration unit and an FPGA preprocessing unit. The data processing module is built-in with a phase unwrapping algorithm, a sub-pixel positioning algorithm, and a noise suppression filter to complete the processing and analysis of a single-frame interference image.

2. The grating interference measurement device based on a large-size light spot according to claim 1, wherein The beam shaper in the collimating and beam expanding module adopts a microlens array structure, and the microlens array is composed of thousands of microlens units with a diameter of 50 - 100μm, for converting a laser beam with a Gaussian distribution into a flat-top beam with a uniform intensity distribution.

3. The grating interference measurement device based on a large-size light spot according to claim 1, wherein The beam splitting module further includes an optical intensity monitoring unit, which real-time monitors the optical intensities of the reference beam and the measurement beam, and feeds back to the control system to dynamically adjust the rotation angle of the λ / 4 wave plate to keep the intensity ratio of the two beams stable within the range of ±2% of the set value.

4. The grating interference measurement device based on a large-size light spot according to claim 1, wherein, The three-dimensional precision adjustment platform of the reference grating module includes a piezoelectric ceramic driver and a flexible hinge structure. The displacement resolution of the piezoelectric ceramic driver reaches 0.1nm, and the flexible hinge structure is used to reduce the influence of mechanical vibration on the grating position.

5. The grating interference measurement device based on a large-size light spot according to claim 1, wherein, The adaptive height adjustment mechanism of the measurement grating module includes a laser range finder sensor and a closed-loop control system. The laser range finder sensor real-time measures the distance between the surface of the object to be measured and the measurement grating, and the closed-loop control system drives a stepper motor to adjust the position of the measurement grating according to the measurement result.

6. The grating interference measurement device based on a large-size light spot according to claim 1, wherein, The large field of view telecentric imaging lens group of the imaging module includes multiple groups of aspherical lenses and diffractive optical elements. The diffractive optical elements are used to correct high-order aberrations that cannot be eliminated by traditional refractive lenses, so that the spatial resolution within the entire measurement field of view is better than 5μm.

7. The grating interference measurement device based on a large-size light spot according to claim 1, characterized in that The noise suppression filter of the data processing module adopts a composite filtering algorithm combining wavelet transform and Kalman filtering to suppress the influence of environmental vibration, air turbulence and circuit noise on the interference fringes.

8. A measurement method based on grating interference with a large-sized light spot using the device according to any one of claims 1-7, characterized in that, It includes the following steps: Step 1: Initialize the system and set the measurement parameters, including spot size, light intensity ratio, and sampling frequency; Step 2: The light source module emits a stable laser beam, which forms a large-size flat-top parallel beam through the collimation and beam expansion module; Step 3: The beam splitting module divides the large-size parallel beam into a reference beam and a measurement beam, and optimizes the intensity ratio of the two beams by adjusting the angle of the λ / 4 wave plate; Step 4: The reference beam irradiates the reference grating, and the measurement beam irradiates the measurement grating and reflects the surface of the object to be measured, respectively generating reference interference fringes and measurement interference fringes; Step 5: The imaging module collects the interference fringe image and transmits it to the data processing module; Step 6: The data processing module preprocesses the interference fringe image, including denoising, enhancement and positioning; Adopt the Fourier transform phase extraction algorithm to calculate the phase distribution of the interference fringes; Use the phase unwrapping algorithm to eliminate the 2π phase ambiguity and obtain a continuous phase map; According to the phase-height mapping relationship, calculate the three-dimensional topography information of the surface of the object to be measured; Apply the least squares fitting algorithm to optimize the measurement results and improve the measurement accuracy.

9. The measuring method according to claim 8, characterized in that, The phase unwrapping algorithm adopts the quality-guided path tracking method, combined with the reliability map and the reliability ranking strategy, to preferentially unwrap the high-quality phase region to ensure stable propagation during the phase unwrapping process.

10. The measurement method according to claim 8, characterized in that, It also includes a dynamic compensation step. During the measurement process, the changes in environmental temperature, humidity and air pressure are monitored in real time, and the measurement results are corrected in real time using the pre-established environmental parameter-phase error compensation model to eliminate the influence of environmental factors on the measurement accuracy.

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