Multipoint spectrum confocal measurement method

Abstract

The invention discloses a multi-point spectrum confocal measurement method, which comprises the following steps of: transmitting broadband light to an optical fiber light-emitting aperture through an optical fiber network by using a group of broadband light sources to form multi-point irradiation; the broadband light is dispersed through a dispersion lens and is decomposed into dispersion light rays with different wavelengths, and a plurality of groups of dispersion light rays form focused multi-point light beams to irradiate different positions of the workpiece to be measured; receiving reflected light rays from the surface of the workpiece to be detected through at least three optical fiber channels of the multi-channel spectrum analysis device, and analyzing a spectrum signal of each return channel; on the basis of the spectral signals of at least three measurement points, the inclination angle of the plane of the measured workpiece is calculated by adopting the relative height difference between multiple point positions and combining the triangular geometrical relationship with the light path reflection angle; in the whole operation process, the measurement device does not need to be moved, the measurement precision and stability are kept, the method effectively avoids errors caused by a moving shaft in a traditional method, and the measurement efficiency and precision are integrally improved.

Description

Technical Field

[0001] The invention relates to the field of measurement technology, and in particular to a multi-point spectral confocal measurement method. Background Art

[0002] Spectral confocal measurement technology is widely used in modern industry, especially in precision machining, surface inspection, micro-nanostructure measurement, and semiconductor manufacturing. With the continuous improvement of manufacturing processes, the accuracy and efficiency of surface inspection are increasingly required, and traditional two-dimensional surface inspection methods can no longer meet these high-precision requirements. Spectral confocal measurement technology has gradually become an important tool in the field of precision inspection due to its non-contact and high-resolution characteristics. It uses spectral analysis to achieve high-precision measurement of material surface profile, roughness, and other microstructures, and is widely used in scenarios such as plane measurement, thin film thickness measurement, and complex curved surface measurement.

[0003] Existing spectral confocal measurement devices usually use a single point or a row of optical fibers for measurement, and scan the entire surface by mechanically moving the measuring device. Although this method can obtain two-dimensional distribution measurement data, it is easy to introduce mechanical axis movement errors due to the need to constantly move the measuring device, resulting in reduced measurement accuracy. Especially in high-precision measurement scenarios, this mechanical movement method will greatly affect the reliability and stability of the measurement results. In addition, the existing technology can only obtain one-dimensional measurement data through a single point or linearly arranged optical fiber, and it is impossible to obtain multiple measurement point information on the entire plane at one time, which increases the measurement time and difficulty.

[0004] In view of this, it is necessary to improve the spectral confocal measurement device technology in the prior art to solve the technical problem of low precision caused by the mechanical movement measurement process. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-point spectral confocal measurement method to solve the above technical problems.

[0006] To achieve this object, the present invention adopts the following technical solutions: A multi-point spectral confocal measurement method is implemented by a spectral confocal measurement device, wherein the spectral confocal measurement device includes a light source, an optical fiber, a dispersion lens, a multi-channel spectral analysis device, and at least three optical fiber light output apertures arranged in a triangle. The multi-point spectral confocal measurement method includes: Step S1: using a set of broadband light sources to transmit broadband light to the optical fiber light output aperture through an optical fiber network to form multi-point illumination; Step S2: The broadband light is dispersed by a dispersion lens and decomposed into dispersed light rays of different wavelengths. Multiple groups of dispersed light rays form focused multi-point light beams that are irradiated to different positions of the workpiece to be measured; Step S3: receiving reflected light from the surface of the workpiece to be measured through at least three optical fiber channels of the multi-channel spectrum analysis device, and analyzing the spectrum signal of each return channel; Step S4: Based on the spectral signals of at least three measuring points, the relative height difference between the multi-point positions is used to calculate the inclination angle of the plane of the measured workpiece through the triangle geometric relationship combined with the light path reflection angle.

[0007] Optionally, the step S1 specifically includes: Step S11: providing a group of broadband light sources, wherein the broadband light sources are capable of emitting broadband light signals covering a predetermined spectral range; Step S12: Distributing the broadband optical signal to multiple optical fiber channels through the optical fiber network; Step S13: transmitting the broadband light to the corresponding optical fiber light output apertures, wherein the optical fiber light output apertures are arranged in a triangle to form a multi-point illumination layout, thereby realizing simultaneous illumination of different positions of the workpiece to be measured.

[0008] Optionally, the optical fiber network includes an adjustable optical fiber splitter for distributing the broadband optical signal to each optical fiber channel evenly or proportionally as required; Wherein, the optical modulation device is arranged in each optical fiber channel to adjust the amplitude and phase of the broadband light to compensate for the loss and phase deviation in the optical fiber transmission.

[0009] Optionally, the step S3 specifically includes: Step S31: receiving a spectrum signal reflected from the workpiece surface through an optical fiber channel of a multi-channel spectrum analysis device, wherein the optical fiber channel corresponds one-to-one to a corresponding optical fiber light exit aperture; Step S32: preprocessing the received spectral signal, including filtering and noise elimination.

[0010] Optionally, after step S32, the following steps may be further performed: Step S33: input the received multi-channel spectral signal into the spectral analysis device according to the channel respectively, use the spectral analysis algorithm to perform wavelength resolution on the spectrum of each channel, extract the light intensity information corresponding to different wavelengths, and generate the spectral distribution curve of each measurement point; Step S34: synchronize the multi-point spectral data and perform differential analysis, perform time synchronization processing on the spectral distribution curves obtained from at least three optical fiber channels, and make the time sequence of the multi-point spectral data consistent.

[0011] Optionally, the step S4 specifically includes: Step S41: converting the spectral data of each measuring point analyzed into a height value of each measuring point relative to the measuring device based on the wavelength-displacement relationship of the confocal spectrum measurement; Step S42: determining the relative height difference between the multiple measuring points, and calculating the relative height difference between adjacent measuring points by comparing the height information of at least three measuring points; Step S43: construct a triangular geometric model, form a triangle with the coordinates of at least three measuring points, and determine the lengths of the three sides of the triangle using the known relative height difference of each measuring point.

[0012] Optionally, after step S43, the following steps are further included: Step S44: according to the light path reflection principle in the spectral confocal measurement device, the inclination angle is calibrated through the relationship between the light path reflection angle and the surface inclination, so as to correct the measured triangle geometric model; Step S45: Based on the corrected triangular geometric model, the local inclination angle of the workpiece surface is calculated by trigonometric function formulas, and a two-dimensional distribution analysis is performed on the entire surface to generate an inclination distribution map of the workpiece surface, and the inclination angle data is output as a measurement result.

[0013] Optionally, after step S4, the following steps may be further performed: Step S5: According to different measurement requirements, the positions of at least three optical fiber light output apertures are adjusted by a driving component to change the measurement range; Step S6: During the spectral analysis process, the spectral data of different measurement points are normalized, and the spectral changes between adjacent measurement points are used to further optimize the microstructural feature analysis of the reflective surface. The plane inclination and surface roughness are calculated by combining the spectral curve of each measurement point.

[0014] Optionally, the step S6 specifically includes: Step S61: normalizing the light intensity values ​​and spectral curves of different measuring points by performing a standardization operation on the spectral data of each measuring point; Step S62: Analyze the spectral changes between adjacent measurement points, compare the normalized spectral data of at least three measurement points, focus on analyzing the spectral differences between adjacent measurement points, extract the spectral change characteristics of the reflective surface in different areas, and obtain the surface microstructure characteristics; Step S63: constructing a surface microstructure model based on the obtained surface microstructure features and combining the factors of light intensity, wavelength, and reflection angle in spectral confocal measurement; Step S64: by analyzing the normalized spectrum curve of each measurement point, extracting the wavelength-displacement relationship, and combining the relative height difference between multiple points, using the triangle geometric relationship and the spectral reflection angle, calculating the local tilt angle of the workpiece surface; Step S65: Based on the surface microstructure model and the spectral variation information between adjacent measurement points, the microscopic fluctuation characteristics of the surface reflected light are extracted, and the surface roughness is quantitatively calculated using a statistical method to obtain the surface roughness through analysis.

[0015] Compared with the prior art, the present invention has the following beneficial effects: during the measurement process, a broadband light source is transmitted to multiple optical fiber light output apertures through an optical fiber network to form multi-point irradiation to the surface of the workpiece to be measured, ensuring measurement at multiple positions at the same time; the broadband light is dispersed through a dispersion lens, and light of different wavelengths is dispersed and forms focused light beams at multiple points, which are respectively irradiated to different positions of the workpiece to ensure the optical distribution of multi-point measurement; the optical fiber channel in the multi-channel spectral analysis device receives the light reflected from the surface of the workpiece, analyzes the spectral signal of each return channel, and calculates the inclination angle of the workpiece surface based on the spectral signals of at least 3 measuring points through the triangular geometric relationship combined with the reflection angle of the optical path; during the entire operation process, there is no need to move the measuring device to maintain measurement accuracy and stability. This method effectively avoids the error introduced by the moving axis in the traditional method, and improves the efficiency and accuracy of the measurement as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0018] Figure 1 is a schematic diagram of the layout of the spectral confocal measurement device of this embodiment; Figure 2 This is one of the flow charts of the multi-point spectral confocal measurement method of this embodiment; Figure 3 FIG2 is a second flow chart of the multi-point spectral confocal measurement method of this embodiment; Figure 4 This is the third flow chart of the multi-point spectral confocal measurement method of this embodiment. DETAILED DESCRIPTION

[0019] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0021] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0022] The embodiment of the present invention provides a multi-point spectral confocal measurement method, which is implemented by a spectral confocal measurement device. The spectral confocal measurement device includes a light source, a processing circuit 101, an optical fiber network 105, a dispersion lens 104, a multi-channel spectral analysis device 102 and at least three optical fiber light output apertures 103 arranged in a triangle.

[0023] Multi-point spectral confocal measurement methods include: Step S1: using a set of broadband light sources to transmit broadband light to the optical fiber light output aperture 103 through the optical fiber network 105 to form multi-point illumination; A group of broadband light sources is used as the light source, and the broadband light is transmitted to multiple optical fiber light output apertures 103 through the optical fiber network 105. These optical fiber light output apertures 103 are arranged in a triangle to form a multi-point irradiation layout. Through the transmission of the optical fiber network 105, the broadband light can reach multiple measurement points evenly, ensuring that different measurement positions receive the same light source signal, and realizing simultaneous irradiation of different positions of the workpiece to be measured. This layout does not require a moving device, avoiding the measurement inaccuracy caused by mechanical errors in traditional mobile measurement.

[0024] Step S2: The broadband light is dispersed by the dispersion lens 104 and decomposed into dispersed light beams of different wavelengths. Multiple groups of dispersed light beams form focused multi-point light beams that are irradiated to different positions of the workpiece to be measured; The broadband light is spectrally dispersed by the dispersion lens 104 and decomposed into dispersed light of different wavelengths. The dispersed light is focused to multiple measurement points to form a multi-point light beam. These light beams are irradiated to different positions of the workpiece to be measured, and the reflected light information can be obtained at multiple measurement points at the same time. The function of the dispersion lens 104 is to ensure that light of different wavelengths produces different focusing effects at different measurement points, thereby laying the foundation for subsequent spectral analysis. This step further improves the resolution and accuracy of spectral measurement.

[0025] Step S3: receiving reflected light from the surface of the workpiece to be measured through at least three optical fiber channels of the multi-channel spectrum analysis device 102, and analyzing the spectrum signal of each return channel; The optical signal reflected from the surface of the workpiece to be measured is received through at least three optical fiber channels of the multi-channel spectral analysis device 102. Each optical fiber channel corresponds to a measurement point, ensuring that the spectral signal of each return channel can be analyzed separately. By analyzing the reflected light of different wavelengths through the spectral analysis device, the spectral distribution information of each measurement point can be obtained to ensure that the spectral data of each measurement point is independent and accurate, providing an accurate spectral signal basis for the subsequent calculation of the inclination and surface characteristics.

[0026] Step S4: the processing circuit 101 calculates the tilt angle of the plane of the workpiece to be measured based on the spectrum signals of at least three measuring points, using the relative height difference between the multi-point positions, and combining the triangle geometric relationship with the light path reflection angle.

[0027] The final output tilt angle data can be used to reflect the two-dimensional tilt distribution characteristics of the workpiece surface, ensuring accurate measurement results.

[0028] The working principle of the present invention is as follows: during the measurement process, a broadband light source is transmitted to multiple optical fiber light output apertures 103 through an optical fiber network 105, forming multi-point irradiation to the surface of the workpiece to be measured, ensuring that measurements are performed at multiple positions at the same time; the broadband light is dispersed through a dispersion lens 104, and light of different wavelengths is dispersed and forms focused light beams at multiple points, which are respectively irradiated to different positions of the workpiece, ensuring the optical distribution of multi-point measurement; the optical fiber channel in the multi-channel spectral analysis device 102 receives the light reflected from the surface of the workpiece, analyzes the spectral signal of each return channel, and calculates the inclination angle of the workpiece surface based on the spectral signals of at least 3 measurement points through the triangular geometric relationship combined with the reflection angle of the optical path; during the entire operation process, there is no need to move the measuring device to maintain measurement accuracy and stability. This method effectively avoids the error introduced by the moving axis in the traditional method, and improves the efficiency and accuracy of the measurement as a whole.

[0029] In this embodiment, it is specifically explained that step S1 specifically includes: Step S11: providing a set of broadband light sources, wherein the broadband light sources are capable of emitting broadband light signals covering a predetermined spectral range; Broadband optical signals are composed of multiple wavelengths, providing rich spectral information for subsequent spectral analysis. The choice of broadband light source ensures that each measurement point can obtain sufficient light energy and spectral resolution during multi-point measurement, thus supporting multi-dimensional precision measurement.

[0030] Step S12: Distribute the broadband optical signal to multiple optical fiber channels through the optical fiber network 105; the beam splitter in the optical fiber network 105 distributes the optical signal to multiple optical fiber channels evenly or in proportion as needed, and each channel corresponds to an independent measurement point. In this way, the system can achieve synchronous transmission of optical signals at different measurement points, ensure the consistency and stability of the light source signal, and provide a reliable basis for subsequent multi-point measurement and analysis.

[0031] Step S13: The broadband light is transmitted to the corresponding optical fiber light output aperture 103. The optical fiber light output aperture 103 is arranged in a triangle to form a multi-point irradiation layout to achieve simultaneous irradiation of different positions of the workpiece to be measured.

[0032] The broadband optical signal is transmitted to the corresponding optical fiber light exit aperture 103. These optical fiber light exit apertures 103 are arranged in a triangle, constructing a multi-point irradiation layout. Each optical fiber light exit aperture 103 corresponds precisely to a measurement point, ensuring the precise positioning of multi-point irradiation. Through this triangular arrangement layout, not only can multiple measurement positions be irradiated at the same time, but also the error caused by the movement of the measuring device is avoided, which significantly improves the measurement efficiency and accuracy of the system.

[0033] As a preferred solution of this embodiment, the optical fiber network 105 includes an adjustable optical fiber splitter for distributing the broadband optical signal to each optical fiber channel evenly or proportionally as required; Wherein, an optical modulation device is provided in each optical fiber channel for adjusting the amplitude and phase of broadband light to compensate for the loss and phase deviation in optical fiber transmission.

[0034] In this embodiment, it is specifically described that step S3 specifically includes: Step S31: Receive the spectral signal reflected from the workpiece surface through the optical fiber channel of the multi-channel spectral analysis device 102, wherein the optical fiber channel corresponds one-to-one with the corresponding optical fiber light output aperture 103; ensure that the received spectral signal corresponds one-to-one with the position of each measurement point, and realize independent transmission of multi-point spectral data.

[0035] Step S32: preprocessing the received spectral signal, including filtering and noise elimination; using a bandpass filter to remove ambient light and other unnecessary noise interference, ensuring that the received spectral signal is clear and discernible, and enhancing the signal-to-noise ratio of the spectral signal.

[0036] Step S33: input the received multi-channel spectral signal into the spectral analysis device according to the channel respectively, use the spectral analysis algorithm to perform wavelength resolution on the spectrum of each channel, extract the light intensity information corresponding to different wavelengths, and generate the spectral distribution curve of each measurement point.

[0037] Step S34: synchronize multi-point spectral data and perform differential analysis, perform time synchronization processing on the spectral distribution curves obtained from at least three optical fiber channels, and make the timing of multi-point spectral data consistent. At the same time, by comparing the spectral changes at different measurement points, extract the microscopic characteristics of the surface reflected light, and provide data basis for the subsequent calculation of the plane inclination.

[0038] In this embodiment, it is specifically explained that step S4 specifically includes: Step S41: converting the spectral data of each measuring point analyzed into a height value of each measuring point relative to the measuring device based on the wavelength-displacement relationship of the confocal spectrum measurement; Height information is calculated based on the spectral signal at each measurement point, and the peak wavelength position in each spectral signal is directly related to the height of that point.

[0039] Step S42: Determine the relative height difference between multiple measuring points, and calculate the relative height difference between adjacent measuring points by comparing the height information of at least three measuring points; in order to improve the calculation accuracy, a multiple measurement averaging method can be introduced to reduce the height deviation caused by environmental or optical interference.

[0040] Step S43: Construct a triangular geometric model, form a triangle with the coordinates of at least three measuring points, and determine the lengths of the three sides of the triangle using the known relative height difference of each measuring point. The triangle is a local geometric approximation of the workpiece surface, which is used to reflect the tilt state of the area.

[0041] Step S44: according to the light path reflection principle in the spectral confocal measurement device, the inclination angle is calibrated through the relationship between the light path reflection angle and the surface inclination, so as to correct the measured triangle geometric model; Combined with the optical path reflection angle correction plane inclination calculation, ensure that the impact of the fiber incident angle and reflection angle is compensated.

[0042] Step S45: Based on the corrected triangular geometric model, the local inclination angle of the workpiece surface is calculated by trigonometric function formulas, and a two-dimensional distribution analysis is performed on the entire surface to generate an inclination distribution map of the workpiece surface, and the inclination angle data is output as a measurement result.

[0043] In this embodiment, it is further explained that after step S4, the following steps are further included: Step S5: According to different measurement requirements, the positions of at least three optical fiber light output apertures 103 are adjusted by a driving component to change the measurement range; To adapt to the measured surfaces of different shapes, the relative position of the optical fiber aperture is ensured to be stable during the replacement process, avoiding the need to recalibrate the dispersion lens 104 and the spectrum analysis device.

[0044] Step S6: In the process of spectrum analysis, the spectrum data of different measurement points are normalized, and the microstructure feature analysis of the reflective surface is further optimized through the spectrum change between adjacent measurement points. The plane inclination and surface roughness are calculated by combining the spectrum curve of each measurement point. The two-dimensional distribution measurement of the measured surface is realized to ensure high precision and high resolution of the results.

[0045] In this embodiment, it is specifically described that step S6 specifically includes: Step S61: normalize the light intensity values ​​and spectral curves of different measuring points by standardizing the spectral data of each measuring point, so as to eliminate the errors caused by factors such as light source non-uniformity and measurement angle, and ensure that the data between different measuring points are comparable.

[0046] Step S62: Analyze the spectral changes between adjacent measurement points, compare the normalized spectral data of at least three measurement points, focus on analyzing the spectral differences between adjacent measurement points, extract the spectral change characteristics of the reflective surface in different areas, and obtain the surface microstructure characteristics; this process can reflect the changes in the surface microstructure and help identify surface features and local inhomogeneities.

[0047] Step S63: Based on the obtained surface microstructure features, combined with the factors of light intensity, wavelength, and reflection angle in spectral confocal measurement, a surface microstructure model is constructed; this model can accurately describe the microscopic characteristics of the reflective surface, such as roughness and texture, and further improve the resolution of surface analysis.

[0048] Step S64: by analyzing the normalized spectrum curve of each measurement point, extracting the wavelength-displacement relationship, and combining the relative height difference between multiple points, using the triangle geometric relationship and the spectral reflection angle, calculating the local tilt angle of the workpiece surface; Step S65: Based on the surface microstructure model and the spectral variation information between adjacent measurement points, the microscopic fluctuation characteristics of the surface reflected light are extracted, and the surface roughness is quantitatively calculated using statistical methods to analyze and obtain the surface roughness. This step combines the spectral data of multiple measurement points to generate a roughness distribution map of the workpiece surface in a high-precision manner.

[0049] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-point spectral confocal measurement method, characterized in that: The multi-point spectral confocal measurement method is realized by a spectral confocal measurement device, which includes a light source, an optical fiber, a dispersion lens, a multi-channel spectral analysis device, and at least three optical fiber light output apertures arranged in a triangle. The multi-point spectral confocal measurement method includes: Step S1: using a set of broadband light sources to transmit broadband light to the optical fiber light output aperture through an optical fiber network to form multi-point illumination; Step S2: The broadband light is dispersed by a dispersion lens and decomposed into dispersed light rays of different wavelengths. Multiple groups of dispersed light rays form focused multi-point light beams that are irradiated to different positions of the workpiece to be measured; Step S3: receiving reflected light from the surface of the workpiece to be measured through at least three optical fiber channels of the multi-channel spectrum analysis device, and analyzing the spectrum signal of each return channel; Step S4: Based on the spectral signals of at least three measuring points, the relative height difference between the multi-point positions is used to calculate the inclination angle of the plane of the measured workpiece through the triangle geometric relationship combined with the light path reflection angle.

2. The multi-point spectral confocal measurement method according to claim 1, characterized in that: The step S1 specifically includes: Step S11: providing a group of broadband light sources, wherein the broadband light sources are capable of emitting broadband light signals covering a predetermined spectral range; Step S12: Distributing the broadband optical signal to multiple optical fiber channels through the optical fiber network; Step S13: transmitting the broadband light to the corresponding optical fiber light output apertures, wherein the optical fiber light output apertures are arranged in a triangle to form a multi-point illumination layout, thereby realizing simultaneous illumination of different positions of the workpiece to be measured.

3. The multi-point spectral confocal measurement method according to claim 2, characterized in that: The optical fiber network includes an adjustable optical fiber splitter for distributing broadband optical signals to each optical fiber channel evenly or proportionally as required; Wherein, the optical modulation device is arranged in each optical fiber channel to adjust the amplitude and phase of the broadband light to compensate for the loss and phase deviation in the optical fiber transmission.

4. The multi-point spectral confocal measurement method according to claim 1, characterized in that: The step S3 specifically includes: Step S31: receiving a spectrum signal reflected from the workpiece surface through an optical fiber channel of a multi-channel spectrum analysis device, wherein the optical fiber channel corresponds one-to-one to a corresponding optical fiber light exit aperture; Step S32: preprocessing the received spectral signal, including filtering and noise elimination.

5. The multi-point spectral confocal measurement method according to claim 1, characterized in that: After step S32, the following steps are also included: Step S33: input the received multi-channel spectral signal into the spectral analysis device according to the channel respectively, use the spectral analysis algorithm to perform wavelength resolution on the spectrum of each channel, extract the light intensity information corresponding to different wavelengths, and generate the spectral distribution curve of each measurement point; Step S34: synchronize the multi-point spectral data and perform differential analysis, perform time synchronization processing on the spectral distribution curves obtained from at least three optical fiber channels, and make the time sequence of the multi-point spectral data consistent.

6. The multi-point spectral confocal measurement method according to claim 1, characterized in that: The step S4 specifically includes: Step S41: converting the spectral data of each measuring point analyzed into a height value of each measuring point relative to the measuring device based on the wavelength-displacement relationship of the confocal spectrum measurement; Step S42: determining the relative height difference between the multiple measuring points, and calculating the relative height difference between adjacent measuring points by comparing the height information of at least three measuring points; Step S43: construct a triangular geometric model, form a triangle with the coordinates of at least three measuring points, and determine the lengths of the three sides of the triangle using the known relative height difference of each measuring point.

7. The multi-point spectral confocal measurement method according to claim 6, characterized in that: After step S43, the following steps are further included: Step S44: according to the light path reflection principle in the spectral confocal measurement device, the inclination angle is calibrated through the relationship between the light path reflection angle and the surface inclination, so as to correct the measured triangle geometric model; Step S45: Based on the corrected triangular geometric model, the local inclination angle of the workpiece surface is calculated by trigonometric function formulas, and a two-dimensional distribution analysis is performed on the entire surface to generate an inclination distribution map of the workpiece surface, and the inclination angle data is output as a measurement result.

8. The multi-point spectral confocal measurement method according to claim 1, characterized in that: After step S4, the following steps are also included: Step S5: According to different measurement requirements, the positions of at least three optical fiber light output apertures are adjusted by a driving component to change the measurement range; Step S6: During the spectral analysis process, the spectral data of different measurement points are normalized, and the spectral changes between adjacent measurement points are used to further optimize the microstructural feature analysis of the reflective surface. The plane inclination and surface roughness are calculated by combining the spectral curve of each measurement point.

9. The multi-point spectral confocal measurement method according to claim 8, characterized in that: The step S6 specifically includes: Step S61: normalizing the light intensity values ​​and spectral curves of different measuring points by performing a standardization operation on the spectral data of each measuring point; Step S62: Analyze the spectral changes between adjacent measurement points, compare the normalized spectral data of at least three measurement points, focus on analyzing the spectral differences between adjacent measurement points, extract the spectral change characteristics of the reflective surface in different areas, and obtain the surface microstructure characteristics; Step S63: constructing a surface microstructure model based on the obtained surface microstructure features and combining the factors of light intensity, wavelength, and reflection angle in spectral confocal measurement; Step S64: by analyzing the normalized spectrum curve of each measurement point, extracting the wavelength-displacement relationship, and combining the relative height difference between multiple points, using the triangle geometric relationship and the spectral reflection angle, calculating the local tilt angle of the workpiece surface; Step S65: Based on the surface microstructure model and the spectral variation information between adjacent measurement points, the microscopic fluctuation characteristics of the surface reflected light are extracted, and the surface roughness is quantitatively calculated using a statistical method to obtain the surface roughness through analysis.

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