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CN-122016694-A - Fourier infrared spectrum online self-checking diagnosis control method and system

CN122016694ACN 122016694 ACN122016694 ACN 122016694ACN-122016694-A

Abstract

The invention discloses a Fourier infrared spectrum online self-checking diagnosis control method and system, and relates to the technical field of spectrometer diagnosis. The method comprises the following steps of S1, collecting an interference diagram amplitude sequence of each scanning of a spectrometer in real time, preprocessing, identifying a zero optical path difference position to construct an interference diagram central symmetry analysis interval, S2, analyzing mirror symmetry characteristics, evaluating current scanning stability, S3, extracting an envelope amplitude sequence, analyzing disturbance separation characteristics, judging current scanning abnormal sources, S4, identifying disturbance intensity, evaluating current disturbance recovery trend in combination with scanning time intervals, and generating a treatment control strategy. The problems that the stability of the interference pattern is abnormal and is difficult to identify in time, invalid scanning is easy to generate and the spectrum quality and the measurement reliability are affected in the online operation process of the Fourier infrared spectrometer are solved.

Inventors

  • JIA SHUANG
  • FENG ZHIWEI
  • LIU ZHENHAN
  • QIN XIAOXU
  • SU PENG

Assignees

  • 天津市拓普仪器有限公司

Dates

Publication Date
20260512
Application Date
20260416

Claims (10)

  1. 1. The Fourier infrared spectrum online self-checking diagnosis control method is characterized by comprising the following steps of: s1, acquiring an interference pattern amplitude sequence of each scanning of a spectrometer in real time, preprocessing the interference pattern amplitude sequence, identifying a zero optical path difference position based on the interference pattern amplitude sequence, and constructing an interference pattern central symmetry analysis interval; s2, analyzing mirror symmetry characteristics by utilizing an interference pattern amplitude sequence in an interference pattern central symmetry analysis interval, and evaluating the current scanning stability according to the mirror symmetry characteristics; S3, extracting an envelope amplitude sequence based on the interference pattern amplitude sequence, extracting disturbance separation characteristics by combining the envelope amplitude sequence and the interference pattern amplitude sequence, and judging the current scanning abnormality source according to the disturbance separation characteristics; S4, recognizing disturbance intensity by combining the mirror symmetry features and the disturbance separation features, evaluating the current disturbance recovery trend based on the disturbance intensity and the scanning time interval, and generating a corresponding treatment control strategy according to the evaluation result.
  2. 2. The method for controlling the online self-checking diagnosis of the Fourier infrared spectrum according to claim 1, wherein the specific process of preprocessing the interferogram amplitude sequence of each scanning of the real-time acquisition spectrometer is as follows: In the running process of the Fourier infrared spectrometer, collecting online data of the spectrometer of each scanning in real time through an acquisition drive and instrument control interface, wherein the online data of the spectrometer comprises scanning starting time, scanning ending time and an interference pattern amplitude sequence; The method comprises the steps of calculating an average value of an interferogram amplitude sequence, subtracting the average value from an original sequence, performing DC removal on the interferogram amplitude sequence, performing normalization on the interferogram amplitude sequence by dividing the DC-removed interferogram amplitude sequence by the maximum absolute interferogram amplitude, establishing an infrared spectrum online self-checking database, and storing original and preprocessed spectrometer online data.
  3. 3. The method for controlling the online self-checking diagnosis of the Fourier infrared spectrum according to claim 2, wherein the specific process of identifying the zero optical path difference position based on the interference pattern amplitude sequence and constructing the interference pattern central symmetry analysis interval is as follows: The method comprises the steps of selecting sampling points corresponding to absolute values of maximum interferogram amplitude values in an interferogram amplitude value sequence to obtain zero-path difference positions, respectively traversing the interferogram amplitude values along the left side and the right side by taking the zero-path difference positions as the center, calculating the number of sampling points with the interferogram amplitude values continuously larger than or equal to a central peak amplitude proportion threshold value, taking the maximum number of the sampling points in the left side and the right side as a central analysis window length, and determining the extension ranges of the left side and the right side by taking the zero-path difference positions as the center and the central analysis window length to construct a central symmetry analysis interval of the interferogram.
  4. 4. The method for controlling online self-checking diagnosis of fourier spectrum according to claim 3, wherein the specific process of analyzing the image symmetry characteristics by using the interferogram amplitude sequence in the interferogram central symmetry analysis interval is as follows: reading an interference pattern central symmetry analysis interval, multiplying the left sampling point and the interference pattern amplitude corresponding to the right sampling point by each other in the interval, and accumulating all products in the interval to obtain a mirror image product value; Respectively calculating and accumulating squares of the amplitude values of the interferograms corresponding to the left sampling points in the central symmetry analysis interval of the interferograms to obtain left square sums; The square sum of the left side and the square sum of the right side are multiplied after being divided by square respectively to obtain a normalized product value, and the ratio of the mirror image product value to the normalized product value is subtracted by one to obtain a mirror image symmetry deviation value.
  5. 5. The method for controlling online self-checking diagnosis of fourier spectrum as recited in claim 4, wherein the specific process of evaluating the current scanning stability according to the mirror symmetry feature is: comparing the mirror symmetry deviation value with a deviation threshold value, and judging stability: when the mirror symmetry deviation value is smaller than or equal to the deviation threshold value, judging that the current scanning is stable; When the mirror symmetry deviation value is larger than the deviation threshold value, judging that the current scanning is abnormal; and writing the mirror symmetry deviation value and the stability judging result into an infrared spectrum online self-checking database.
  6. 6. The method for controlling the online self-checking diagnosis of the fourier spectrum according to claim 1, wherein the specific process of extracting the disturbance separation characteristic based on the interference pattern amplitude sequence and combining the envelope amplitude sequence and the interference pattern amplitude sequence is as follows: The method comprises the steps of reading an interferogram amplitude sequence in a central symmetry analysis interval of an interferogram, performing Hilbert transformation on the interferogram amplitude sequence to obtain an imaginary part sequence, taking the interferogram amplitude sequence as a complex real part, taking a corresponding imaginary part sequence as a complex imaginary part, constructing a complex sequence, and performing modulo operation on each sampling point in the complex sequence to obtain an interferogram envelope amplitude sequence; performing second-order differential operation on each interferogram amplitude in the interferogram central symmetry analysis interval to obtain second-order differential values of the interferograms, respectively squaring and accumulating all the second-order differential values of the interferograms in the interval, dividing the second-order differential values by the number of sampling points in the interval to subtract two, and square-root dividing the divisor result to obtain a second-order differential standard value; Performing first-order differential operation on each interferogram envelope amplitude in the interferogram central symmetry analysis interval to obtain envelope first-order differential values, respectively squaring and accumulating all envelope first-order differential values in the interval, dividing the values by the number of sampling points in the interval to subtract one, and square-root dividing the divisor result to obtain envelope first-order differential standard values; dividing the second-order differential standard value by the sum of the envelope first-order differential standard value and the minimum positive number to obtain a vibration envelope disturbance separation value.
  7. 7. The method for controlling online self-checking diagnosis of fourier spectrum as recited in claim 6, wherein the specific process of determining the source of the current scanning anomaly according to the disturbance separation characteristic comprises: when the current scanning abnormality is judged, if the vibration envelope disturbance separation value is larger than or equal to the separation judgment threshold value, judging that the current scanning abnormality source is mechanical vibration abnormality; when the current scanning is determined to be stable, only recording vibration envelope disturbance separation values; and writing the vibration envelope disturbance separation value and the abnormal type into an infrared spectrum online self-checking database.
  8. 8. The method for controlling online self-checking diagnosis of fourier spectrum according to claim 7, wherein the integrated mirror symmetry feature and disturbance separation feature identify disturbance intensity, and the specific process of evaluating the current disturbance recovery trend based on the disturbance intensity and the scanning time interval is as follows: Multiplying the vibration envelope disturbance separation value by the mirror symmetry deviation value to obtain a scanning disturbance intensity value, subtracting the natural logarithm of the current scanning disturbance intensity value from the natural logarithm of the last scanning disturbance intensity value to obtain a disturbance change amplitude, subtracting the last scanning ending time from the current scanning ending time to obtain a scanning time interval, dividing the disturbance change amplitude by the scanning time interval to obtain a disturbance attenuation rate; Reading a corresponding scanning disturbance intensity value of the historical scanning stabilization, taking the median, calculating the median absolute deviation, adding three times of the median absolute deviation to obtain a normal disturbance reference value, subtracting the natural logarithm of the normal disturbance reference value from the natural logarithm of the current scanning disturbance intensity value, and dividing the natural logarithm by the disturbance attenuation rate to obtain recovery waiting time.
  9. 9. The method for controlling online self-checking diagnosis of fourier spectrum according to claim 8, wherein the specific process of generating the corresponding treatment control strategy according to the evaluation result is as follows: When the current scan is determined to be abnormal, calculating the disturbance decay rate and the recovery waiting time, and generating a treatment control strategy: If the disturbance attenuation rate is greater than zero, executing delay waiting according to the recovery waiting time, and rescanning after waiting is finished; if the disturbance attenuation rate is less than or equal to zero, judging that the abnormality is not attenuated, triggering a recovery strategy, namely stopping scanning, generating a control instruction for restarting the Fourier infrared spectrometer, and generating a prompt for checking the equipment and environment states and re-collecting the background.
  10. 10. A fourier infrared spectroscopy on-line self-test diagnostic control system, comprising: The online data acquisition processing module is used for acquiring an interference pattern amplitude sequence of each scanning of the spectrometer in real time, preprocessing the interference pattern amplitude sequence, identifying a zero optical path difference position based on the interference pattern amplitude sequence, and constructing an interference pattern central symmetry analysis interval; the interference pattern quality evaluation module is used for analyzing mirror symmetry characteristics by utilizing an interference pattern amplitude sequence in an interference pattern central symmetry analysis interval and evaluating the current scanning stability according to the mirror symmetry characteristics; the anomaly diagnosis judging module is used for extracting an envelope amplitude sequence based on the interference diagram amplitude sequence, extracting disturbance separation characteristics by combining the envelope amplitude sequence and the interference diagram amplitude sequence, and judging the current scanning anomaly source according to the disturbance separation characteristics; and the recovery control treatment module is used for integrating the mirror symmetry characteristic and the disturbance separation characteristic to identify disturbance intensity, evaluating the current disturbance recovery trend based on the disturbance intensity and the scanning time interval, and generating a corresponding treatment control strategy according to the evaluation result.

Description

Fourier infrared spectrum online self-checking diagnosis control method and system Technical Field The invention relates to the technical field of spectrometer diagnosis, in particular to a Fourier infrared spectrum online self-checking diagnosis control method and system. Background The spectrometer is an important analysis and detection device and is widely applied to the fields of industrial manufacture, medicine detection, food safety, environmental monitoring, material analysis, scientific research experiments and the like. With the continuous expansion of detection scenes and the continuous improvement of the integration level of software and hardware of instruments, a spectrometer is gradually developed from traditional independent test equipment to a data acquisition and analysis platform capable of operating cooperatively with a computer, and plays an increasingly important role in application scenes such as continuous detection, process monitoring, laboratory automation, online quality control and the like. For example, chinese patent CN112578728B discloses a switching device and a switching method for switching gas of an ICP spectrometer, wherein the switching device comprises a power supply, a torsion stepping motor, a positionable stepping motor driver, a PLC (programmable logic controller), a user terminal, a two-way stainless steel valve and a coupler, wherein the two-way stainless steel valve is arranged on a connecting pipeline, one end of the coupler is connected to the two-way stainless steel valve, the other end of the coupler is connected with the torsion stepping motor, the positionable stepping motor driver is arranged on the torsion stepping motor and is electrically connected with the torsion stepping motor, the PLC is respectively electrically connected with the positionable stepping motor driver, the power supply and the two-way stainless steel valve, and the PLC is remotely connected with the user terminal in a long-distance communication mode. For example, chinese patent CN105676725A discloses a signal acquisition control system for a spark spectrometer, which belongs to the technical field of spark spectrometers. The system comprises a PC, a network cable, a data acquisition and transmission processing module, a serial port line and a negative high voltage control module. The PC and the data acquisition, transmission and processing module are communicated through the Ethernet, the negative high voltage control module outputs multiple paths of negative high voltage control signals, and the data acquisition, transmission and processing module acquires, processes and transmits the output signals of the multichannel photoelectric detector. The method has the advantages that the method adopts high-resolution high-speed parallel AD to collect element spectral line intensity, so that the collection speed is high, the precision is high, negative high voltage applied to the photoelectric detector is set by adopting multichannel DA, real-time digital control of the negative high voltage of the multichannel is realized, each function of the system is processed in parallel and in real time by adopting FPGA as a main controller, built-in FIFO of the FPGA is used for storage, real-time storage and processing of spectral line intensity signals are realized, and communication reliability is improved by communicating with a PC through Ethernet. However, during operation of a fourier infrared spectrometer, the interferograms produced by the interferometer scans are the fundamental data of the spectral calculation, the stability of which directly influences the final spectral quality. In an actual online operation scenario, the interferogram is susceptible to various dynamic factors, such as instrument platform vibration, light source transient fluctuation, scanning speed variation, and ambient airflow disturbance, which may cause the center peak of the interferogram to shift, symmetry break, or periodic structure distortion. When the degree of abnormality is light, the traditional system still always scans and outputs a spectrum, but the signal to noise ratio of the obtained spectrum is reduced or a base line is distorted, and when the degree of abnormality is heavy, the problems of scanning failure or incapacity of calculating the spectrum may occur. Because interferogram anomalies are often found after spectrum calculation is completed, consumed scanning time and calculation resources cannot be utilized, and a large amount of invalid scanning data can be generated under continuous monitoring or on-line analysis scenes, so that measurement efficiency and data reliability are affected. Therefore, in view of the above problems, there is a need for a fourier infrared spectroscopy online self-test diagnostic control method and system. Disclosure of Invention Technical problem to be solved Aiming at the defects of the prior art, the invention provides a Fourier infrared spectrum online self-checking