CN-122015689-A - Non-contact laser micro-nano measurement dynamic adjustment system and method

CN122015689ACN 122015689 ACN122015689 ACN 122015689ACN-122015689-A

Abstract

The invention discloses a non-contact type laser micro-nano measurement dynamic adjusting system and a non-contact type laser micro-nano measurement dynamic adjusting method, which relate to the technical field of laser micro-nano measurement, and the invention introduces fixed motion track parameters of an object to be measured, generates motor pre-judging motion instructions, drives a motor to synchronously run, locks a region to be measured and records the motion track parameters of the motor; the method comprises the steps of processing a laser beam, irradiating a region to be detected, recording initial light path parameters, detecting reflected light signals through an illuminance sensor, constructing a light reflection path model based on motor motion track parameters and the initial light path parameters when effective reflected light is not captured, calculating to obtain motor displacement compensation quantity, adjusting the relative position of the region to be detected and a light path according to the motor displacement compensation quantity until the effective reflected light is captured, collecting reflected light measurement data, converting the reflected light measurement data into digital signals, and calculating to obtain depth data and width data of a sample through fitting processing of a point cloud algorithm.

Inventors

TIAN LIGUO
WENG ZHANKUN
JIANG DONGLIN
MA SIHAN
LIU TIANHUI
YANG JINRU
ZHANG JIAYIN
LI XINXIN
YU MIAO
LIU LANJIAO

Assignees

长春理工大学

Dates

Publication Date: 20260512
Application Date: 20260302

Claims (10)

1.A non-contact laser micro-nano measurement dynamic adjustment method is characterized by comprising the following steps: The method comprises the steps of importing fixed motion track parameters of an object to be detected, generating motor pre-judging motion instructions, driving a motor to run synchronously, locking a region to be detected of the object to be detected through closed loop adjustment of the position of the motor, and recording the motor motion track parameters; Transmitting laser beams, irradiating the laser beams to a locked area to be detected after processing, and recording initial light path parameters; When effective reflected light is not captured, a light reflection path model is built based on the motor motion track parameters and the initial light path parameters; Based on the motor displacement compensation quantity, adjusting the relative position of the region to be measured and the light path until the illuminance sensor captures effective reflected light, acquiring measurement data and converting the measurement data into a digital signal; And according to the obtained digital signals, carrying out fitting processing by a point cloud algorithm, and calculating to obtain depth data and width data of the sample.
2. The method for dynamically adjusting non-contact laser micro-nano measurement according to claim 1, wherein the step of introducing the fixed motion track parameters of the object to be measured, generating the motor pre-judgment motion command, and driving the motors to run synchronously comprises the steps of: Obtaining and importing fixed motion track parameters of an object to be detected, wherein the fixed motion track parameters comprise a dynamic motion track equation, relative position coordinates of a region to be detected and X, Y, Z axis motion speed curves, obtaining a region to be detected pre-judging dynamic center coordinate at each moment through a cubic spline interpolation track analysis algorithm in real time, planning the running speed of a X, Y, Z axis motor according to the region to be detected pre-judging dynamic center coordinate, generating a motor pre-judging motion instruction, comprising dynamic running speeds of all axes, real-time target tracking coordinates and preset displacement amounts of all axes, and driving the X, Y, Z axis motor to synchronously run according to the motor pre-judging motion instruction.
3. The method for dynamically adjusting the micro-nano measurement of the non-contact laser according to claim 1, wherein the step of locking the area to be measured of the object to be measured by adjusting the position of the motor in a closed loop, and recording the parameters of the motion trail of the motor comprises the following steps: The method comprises the steps of acquiring actual positions of all shafts in real time through a motor-integrated position sensor, obtaining actual measurement dynamic center coordinates of a current region to be measured through conversion, comparing the actual measurement dynamic center coordinates of the region to be measured with preset dynamic center coordinates of the region to be measured to obtain position deviation values, correcting the positions of the motors in real time through a PID closed loop regulation algorithm when the position deviation values exceed preset positioning deviation threshold values, judging that locking of the region to be measured is completed when the position deviation values are smaller than or equal to the preset positioning deviation threshold values, and recording motor movement track parameters including X, Y, Z shaft actual displacement values, the actual measurement dynamic center coordinates of the region to be measured and shaft displacement synchronous errors, wherein the shaft displacement synchronous errors are absolute values of the difference values of the actual displacement values of all shafts and preset shaft displacement values.
4. The method for dynamically adjusting non-contact laser micro-nano measurement according to claim 1, wherein the emitting laser beam irradiates the locked area to be measured after processing, records initial optical path parameters, and comprises: The method comprises the steps of emitting laser beams through a laser, sequentially passing through beam expander collimation, cube spectroscope reflection and steering, high-power objective lens focusing and diaphragm inhibition of non-focal scattered light to complete beam processing, guiding the processed laser beams to a locked to-be-detected area to measure dynamic center coordinates, and recording initial optical path core parameters including beam propagation directions after beam processing, beam expander optical path optimization parameters, cube spectroscope reflection angle parameters, high-power objective lens focusing configuration parameters and diaphragm aperture parameters.
5. The method for dynamically adjusting non-contact laser micro-nano measurement according to claim 1, wherein the step of detecting the reflected light signal in real time by the illuminance sensor to obtain the capturing result of the effective reflected light comprises the steps of: the method comprises the steps of capturing reflected light signals of a region to be detected in real time through an illuminance sensor, determining that effective reflected light is captured when the peak value of the reflected light intensity signals detected by the illuminance sensor is larger than a preset effective light intensity threshold value and the duration time is larger than a preset effective time threshold value, and determining that effective reflected light is not captured when at least one condition is not met.
6. The method for dynamic adjustment of non-contact laser micro-nano measurement according to claim 1, wherein when effective reflected light is not captured, constructing a light reflection path model based on the motor motion track parameter and the initial light path parameter comprises: When the effective reflected light is not captured, a motor motion track parameter and an initial light path parameter are called and used as input parameters of a light reflection path model, a three-dimensional rectangular coordinate system is established by taking an actual measurement dynamic center coordinate of a region to be detected as an original point, three-dimensional coordinates of a beam expander, a cubic spectroscope, a high-power objective lens and a diaphragm are calculated according to the physical installation distance of each optical element and the initial light path parameter and mapped into the three-dimensional rectangular coordinate system; Generating an initial incident ray direction vector by taking the coordinates of an emitting point of a laser as a starting point and combining the propagation direction of a light beam and the correction coefficient of the divergence angle of the light beam, and sequentially substituting the initial incident ray direction vector into conversion parameters of each optical element to obtain an incident ray linear equation; And the construction of the light reflection path model is completed through parameter calling, coordinate system construction, parameter conversion and incident light and reflected light track calculation logic.
7. The method for dynamically adjusting non-contact laser micro-nano measurement according to claim 1, wherein the obtaining the motor displacement compensation amount based on the light reflection path model through calculation comprises the following steps: Extracting effective geometric parameters of the receiving surface of the existing illuminance sensor, including plane equations and effective boundary coordinates of the receiving surface, combining a reflected light linear equation output by a constructed light reflection path model with the plane equations of the receiving surface, calculating to obtain theoretical falling point coordinates of reflected light, comparing the theoretical falling point coordinates with the effective boundary coordinates of the receiving surface to obtain deviation directions and deviation distances of the reflected light which does not fall on the receiving surface of the illuminance sensor, calculating logic based on tracks of incident light and reflected light in the light reflection path model, deducing reversely according to the deviation directions and the deviation distances to obtain laser incident angle correction and laser focusing point correction required by eliminating deviation, and converting the laser incident angle correction and the laser focusing point correction into displacement adjustment requirements of X, Y, Z-axis motors as motor displacement compensation quantities, wherein the motor displacement compensation directions and compensation quantity values comprise all-axis motors.
8. The method for dynamically adjusting the micro-nano measurement of the non-contact laser according to claim 1, wherein the adjusting the relative position of the area to be measured and the optical path based on the motor displacement compensation amount until the illuminance sensor captures the effective reflected light, obtaining the measurement data and converting the measurement data into the digital signal comprises: According to the displacement compensation quantity of the motor, a motor linkage control instruction is generated, the X, Y, Z-axis motor is driven to move, the relative position of a region to be detected and a light path is adjusted, the incident angle of a laser beam is changed, in the process that the motor executes adjustment action, a reflected light signal of the region to be detected is continuously captured through an illuminance sensor, when effective reflected light is captured, reflected light measurement data of a current light path, including reflected light intensity distribution, optical path difference and reflected light phase information, are obtained, the obtained reflected light measurement data are converted into digital signals, and the digital signals are stored after filtering noise reduction processing.
9. The method for dynamically adjusting non-contact laser micro-nano measurement according to claim 1, wherein the step of obtaining depth data and width data of the sample by resolving through fitting processing of a point cloud algorithm according to the obtained digital signal comprises the following steps: Converting the stored digital signals into three-dimensional space point cloud data, specifically calculating Z-axis coordinates of each measuring point according to reflected light phase information and optical path difference quantized data, calculating X-axis coordinates and Y-axis coordinates of each measuring point according to reflected light intensity distribution quantized data and laser beam scanning tracks, and forming a three-dimensional point cloud data set; The method comprises the steps of preprocessing a three-dimensional point cloud data set, sequentially performing point cloud deduplication, statistical filtering and data downsampling to obtain preprocessed point cloud data, adopting a point cloud fitting algorithm to process the preprocessed point cloud data, solving sample depth data and sample width data, wherein the solving of the sample depth data is specifically that the point cloud data of a sample region to be detected is selected, a three-dimensional curved surface equation of the sample surface is obtained through least square fitting, an X-Y plane of a three-dimensional rectangular coordinate system is used as a preset reference plane, Z-axis distance between each point on the curved surface equation and the reference plane is calculated, sample depth data of corresponding positions is represented, maximum value, minimum value and distribution gradient in the sample depth data are extracted, complete depth information is formed, the solving of the sample width data is specifically that a projection point set of the three-dimensional point cloud data on the preset reference plane is extracted, a Canny edge detection algorithm is adopted to identify boundary contour of the projection point set, a boundary contour closed curve is obtained through a polynomial, width data of the closed curve in the preset measuring direction is calculated, the maximum distance data of the sample in the corresponding direction is represented, and the depth data and the maximum distance of the sample is output.
10. A non-contact laser micro-nano measurement dynamic adjustment system, using a non-contact laser micro-nano measurement dynamic adjustment method according to any one of claims 1-9, comprising: The system comprises an optical module, a measuring module, a control module, a dynamic adjusting module and a point cloud computing module; The optical module is used for adjusting light beams and focusing the light beams to the surface of a sample to be detected and comprises a laser, a cubic spectroscope, a high-power objective lens and a diaphragm, wherein the laser emits light beams, the light beams are expanded and collimated by the beam expander to optimize the light beam characteristics, the light beams are reflected by the cubic spectroscope, the reflected light beams are focused by the high-power objective lens, non-focus scattered light is restrained by the diaphragm, and the light beams are led to a region to be detected of the sample to be detected; The measuring module is used for acquiring the measurement data related to the reflected light and comprises an illuminance sensor, wherein after the light beam irradiates the sample through the optical module, the reflected light on the surface of the sample is captured by the illuminance sensor to acquire the measurement data; The control module is used for controlling the system to start and stop, receiving measurement data, converting analog and digital signals and comprises a core control unit, a sensor unit and a digital-to-analog conversion module, wherein the core control unit starts equipment, receives the measurement data transmitted by the measurement module through the sensor unit, and converts the analog measurement data into the digital signals through the digital-to-analog conversion module; The dynamic adjustment module is used for receiving the motor displacement compensation quantity of the control module, generating X, Y, Z-axis motor control instructions, driving the motor to operate, collecting the actual position of the motor through the position sensor, feeding back the actual position, and adjusting and correcting deviation through a PID closed loop until the illuminance sensor captures effective reflected light, so that the dynamic positioning of the region to be measured is realized; The point cloud computing module is used for resolving the depth and width data of the sample micro-nano structure in real time, receiving the digital signals of the control module, and obtaining the depth and width data of the sample through fitting processing of a point cloud algorithm.

Description

Non-contact laser micro-nano measurement dynamic adjustment system and method Technical Field The invention relates to the technical field of laser micro-nano measurement, in particular to a non-contact laser micro-nano measurement dynamic adjusting system and method. Background In the field of laser micro-nano manufacturing, accurate measurement of sample surface morphology is a core premise of guaranteeing machining precision and forming quality, but the measurement requirement of the method has requirements on dynamic adaptability, compensation precision and resolution reliability of the technology, and the prior art has a plurality of key short plates, so that the actual application requirement is difficult to meet. In the prior art, the dynamic characteristics of the object to be measured are not considered, the measurement and positioning links are designed for static or simple motion scenes, the fixed motion track parameters of the object to be measured are not imported, the position of the dynamic area to be measured cannot be prejudged in advance, and passive adjustment is carried out only by means of real-time position feedback, so that dynamic positioning lag is caused, and the precision is low. The traditional method does not consider the condition that reflected light does not irradiate the illuminance sensor, when the reflected light deviates from the sensor due to light path deviation, component shielding, sample morphology change and the like, a correlation model of a motor motion track and light path parameters is lacking, the displacement compensation quantity required by the motor cannot be quantitatively calculated, only manual experience or blind debugging can be relied on, the adjustment efficiency is low, new errors are easily introduced, and the measurement continuity is seriously affected. In the prior art, an accurate calculation link from measurement data to sample depth and width data is not formed, standardized digital signal conversion, point cloud processing and fitting resolving processes are lacked, sample depth and width data cannot be reliably output, and accurate planning of a subsequent processing path is difficult to support. Disclosure of Invention The invention aims to provide a non-contact laser micro-nano measurement dynamic adjusting system and a non-contact laser micro-nano measurement dynamic adjusting method, which are used for solving the problems in the prior art. In order to achieve the above purpose, the present invention provides the following technical solutions: in a first aspect, the present invention provides a method for dynamically adjusting non-contact laser micro-nano measurement, including: The method comprises the steps of importing fixed motion track parameters of an object to be detected, generating motor pre-judging motion instructions, driving a motor to run synchronously, locking a region to be detected of the object to be detected through closed loop adjustment of the position of the motor, and recording the motor motion track parameters; Transmitting laser beams, irradiating the laser beams to a locked area to be detected after processing, and recording initial light path parameters; When effective reflected light is not captured, a light reflection path model is built based on the motor motion track parameters and the initial light path parameters; Based on the motor displacement compensation quantity, adjusting the relative position of the region to be measured and the light path until the illuminance sensor captures effective reflected light, acquiring measurement data and converting the measurement data into a digital signal; And according to the obtained digital signals, carrying out fitting processing by a point cloud algorithm, and calculating to obtain depth data and width data of the sample. With reference to the first aspect, in a first implementation manner of the first aspect of the present application, the importing a fixed motion track parameter of an object to be measured, generating a motor pre-judging motion instruction, and driving a motor to run synchronously includes: Obtaining and importing fixed motion track parameters of an object to be detected, wherein the fixed motion track parameters comprise a dynamic motion track equation, relative position coordinates of a region to be detected and X, Y, Z axis motion speed curves, obtaining a region to be detected pre-judging dynamic center coordinate at each moment through a cubic spline interpolation track analysis algorithm in real time, planning the running speed of a X, Y, Z axis motor according to the region to be detected pre-judging dynamic center coordinate, generating a motor pre-judging motion instruction, comprising dynamic running speeds of all axes, real-time target tracking coordinates and preset displacement amounts of all axes, and driving the X, Y, Z axis motor to synchronously run according to the motor pre-judging motion instruction. With reference to the f