Fast and High-Precision Swept-Frequency Interferometric Measurement Signal Processing Method

Abstract

A signal processing method for fast and high-precision swept-frequency interferometry, which relates to the technical field of target absolute distance measurement. In the prior art, there is a problem that the change of the target distance brings pressure to the signal processing end, resulting in low measurement efficiency. In order to improve the efficiency while achieving high-precision measurement, the technology provided by the present invention includes: separately collecting a measurement signal and an auxiliary signal; roughly measuring the frequency of the measurement signal to obtain a frequency reduction multiple; performing modulation and filtering processing on the measurement signal and the auxiliary signal to obtain a processed signal; performing phase demodulation and downsampling on the auxiliary signal in the processed signal, generating a downsampled signal by using the frequency reduction multiple, and performing downsampling processing on the measurement signal in the processed signal; performing downsampling on the phase of the auxiliary signal and the measurement signal in the processed signal; performing nonlinear correction on the downsampled signal, and obtaining the absolute distance of the target through spectral analysis. It is suitable for high-precision ranging and precise positioning work.

Description

Technical Field

[0001] It relates to the technical field of target absolute distance measurement, and specifically relates to a signal processing method for fast and high-precision swept-frequency interference measurement. Background Art

[0002] The swept-frequency interference measurement technology based on frequency-modulated continuous wave (FMCW) has the advantages of unambiguous ranging, no need for a guide rail, and high measurement accuracy, so it is widely used in the fields of aerospace, industrial manufacturing, etc. Its basic principle is to use the frequency difference between the transmitted signal and the echo signal to determine the target absolute distance. An ideal linearly modulated continuous wave has the measurement ability of high range resolution. However, the measurement spectrum broadening caused by the non-linearity of the laser frequency sweep will lead to a significant decrease in the absolute distance measurement accuracy. Therefore, "effectively correcting the frequency sweep non-linearity" is an important guarantee for realizing high-precision swept-frequency interference absolute distance measurement.

[0003] The methods for correcting frequency modulation non-linearity are mainly divided into the phase-locked loop method, the phase comparison method, and the optical frequency monitoring method. In 2009, Peter A Rose et al. from the University of Montana proposed a laser frequency modulation non-linearity correction technology based on the self-heterodyne technique. This technology uses a complex phase-locked loop to correct the frequency modulation non-linearity, which is not only difficult to physically implement but also cannot be applied to the full spectral range. In 2014, Dale et al. realized absolute distance measurement using the phase comparison method. This scheme uses the phase proportional relationship between the auxiliary interference signal and the measurement interference signal to determine the optical path difference of the measurement interferometer. However, this scheme needs to set up a target to obtain high-quality measurement signals, so it cannot measure non-cooperative targets.

[0004] Currently, the optical frequency monitoring method is usually used in the field to realize the correction of frequency sweep non-linearity. Its main idea is to use the linear relationship between the phase of the swept-frequency interference signal and the optical frequency. The frequency-domain sampling method based on the optical frequency monitoring idea was first proposed in 1993. Such methods need to resample the measurement interferometer signal. To ensure accuracy, the sampling rate of the resampling sequence is at least twice that of the measurement interferometer signal. However, as the target distance increases continuously, the increase in the sampling rate of the resampling sequence will bring pressure to the processing end, resulting in a decrease in the measurement efficiency. Subsequently, in 2010, Jiang Yuesong et al. from Beihang University introduced non-linearity using optical devices based on the idea of real-time optical frequency monitoring to suppress the frequency sweep non-linearity. This scheme is the same as the phase-locked loop scheme, which is difficult to physically implement and increases the complexity of the system. In 2016, Liu Zhigang from Xi'an Jiaotong University proposed a method for real-time tracking of the optical frequency based on the non-stationary signal order tracking method. However, this method is still affected by the number of processing points and is not conducive to realizing fast measurement. Summary of the Invention

[0005] To solve the problem that the measurement efficiency is reduced and the fast measurement ability of the measurement system is limited due to the disadvantages such as complex algorithms and large computational amounts existing in the existing swept-frequency interference measurement technology, the technical solution provided by the present invention is as follows;

[0006] A signal processing method for fast and high-precision swept-frequency interference measurement, the method comprising;

[0007] Steps of separately collecting a measurement signal and an auxiliary signal;

[0008] Steps of roughly measuring the frequency of the measurement signal and solving the down-conversion multiple;

[0009] Steps of modulating and filtering the measurement signal and the auxiliary signal to obtain a processed signal;

[0010] Steps of performing phase demodulation and downsampling on the auxiliary interferometer signal in the processed signal, generating a down-converted signal by using the down-conversion multiple, and performing down-conversion processing on the measurement interferometer signal by using the down-converted signal;

[0011] Steps of performing downsampling on the phase of the auxiliary signal and the measurement signal in the processed signal;

[0012] Steps of performing non-linear correction on the down-converted signal and obtaining the absolute distance of the target through spectral analysis.

[0013] Further, a preferred implementation manner is provided. The frequency of the measurement signal is roughly measured by taking a partial number of points for Fourier transform or performing Fourier transform by channels.

[0014] Further, a preferred implementation manner is provided. A modulation signal is generated by a computer, and the modulation signal is multiplied by the measurement signal and the auxiliary signal respectively and then subjected to filtering processing.

[0015] Further, a preferred implementation manner is provided. The phase of the modulated and filtered auxiliary signal is demodulated and downsampled to obtain its phase. Combining the down-conversion multiple, a down-converted signal is generated, and the modulated and filtered measurement signal is down-converted by using the down-converted signal.

[0016] Further, a preferred implementation manner is provided. Non-linear correction is performed on the real part of the down-converted signal according to the corrected phase.

[0017] Further, a preferred implementation manner is provided. The signal after non-linear correction is subjected to spectral analysis to obtain the signal frequency, and the signal frequency is up-converted. The absolute distance of the target to be measured can be obtained through calculation.

[0018] Based on the same inventive concept, the present invention further provides a signal processing device for fast and high-precision swept-frequency interference measurement, the device comprising;

[0019] A module for separately collecting measurement signals and auxiliary signals;

[0020] A module for roughly measuring the frequency of the measurement signal and solving the down-conversion multiple;

[0021] A module for modulating and filtering the measurement signal and the auxiliary signal to obtain a processed signal;

[0022] A module for phase demodulating and downsampling the processed auxiliary signal, generating a down-converted signal using the down-conversion multiple, and down-converting the measurement signal in the processed signal;

[0023] A module for non-linearly correcting the down-converted signal and obtaining the absolute distance of the target through spectral analysis.

[0024] Based on the same inventive concept, the present invention also provides a computer storage medium for storing a computer program, and when the computer program is read by a computer, the computer executes the method.

[0025] Based on the same inventive concept, the present invention also provides a computer including a processor and a storage medium, and when the processor reads the computer program stored in the storage medium, the computer executes the method.

[0026] Based on the same inventive concept, the present invention also provides a computer program product including a computer program, and when the computer program is executed by a processor, the method is implemented.

[0027] Compared with the prior art, the beneficial effects of the technical solution provided by the present invention are as follows;

[0028] The fast and high-precision swept-frequency interference measurement signal processing method provided by the present invention roughly measures the frequency of the measurement signal and calculates the down-conversion multiple. After roughly measuring the frequency, the down-conversion multiple is quickly determined, greatly accelerating the signal processing speed. The frequency range of the signal is reduced, reducing the computational complexity of subsequent processing.

[0029] The fast and high-precision swept-frequency interference measurement signal processing method provided by the present invention generates a modulation signal and modulates and filters the measurement signal and the auxiliary signal. The modulation signal can be used to generate complex signals of the measurement interferometer and the auxiliary interferometer, facilitating subsequent processing.

[0030] The fast and high-precision swept-frequency interference measurement signal processing method provided by the present invention requires precise measurement of all points in the traditional method, which is computationally complex and time-consuming. This solution simplifies the calculation process and saves time by roughly measuring the frequency.

[0031] The fast and high-precision swept-frequency interference measurement signal processing method provided by the present invention demodulates the phase of the filtered auxiliary signal, and uses the phase of the auxiliary signal to achieve down-conversion of the measurement signal, making subsequent signal processing and analysis more convenient and reducing the computational complexity. The traditional method of directly processing high-frequency signals has a large amount of calculation, while through down-conversion processing, the calculation efficiency is greatly improved. Through down-conversion processing, a measurement signal with a smaller effective spectral range can be obtained, and compared with the traditional method, the down-converted signal is less affected by noise.

[0032] The fast and high-precision swept-frequency interference measurement signal processing method provided by the present invention performs phase demodulation and downsampling on the auxiliary signal, generates a down-converted signal using the down-conversion multiple, and performs down-conversion processing on the measurement signal. Generating the down-converted signal and down-conversion processing down-convert the high-frequency signal into a low-frequency signal, significantly reducing the complexity of signal processing. Downsampling reduces the amount of data and improves the signal processing speed. At the same time, since the sampling duration is not reduced, the measurement resolution is ensured to ensure that the measurement accuracy is almost not lost.

[0033] The fast and high-precision swept-frequency interference measurement signal processing method provided by the present invention performs nonlinear correction on the down-converted signal using the correction phase, and obtains the absolute distance of the target through spectral analysis. Nonlinear correction effectively eliminates the nonlinear error in the swept-frequency process and improves the measurement accuracy. Spectral analysis ensures the accuracy of signal processing and can accurately calculate the absolute distance of the target.

[0034] The fast and high-precision swept-frequency interference measurement signal processing method provided by the present invention is suitable for high-precision ranging and precise positioning work. Description of the Drawings

[0035] Figure 1 It is a schematic structural diagram of a swept-frequency interference measurement device;

[0036] Figure 2 It is a signal processing flow chart;

[0037] Figure 3 It is a schematic diagram of the data channelization principle and simulation results;

[0038] Figure 4 It is a schematic diagram of the absolute distance measurement simulation results. Detailed Embodiments

[0039] To make the advantages and beneficial effects of the technical solution provided by the present invention more clearly reflected, the technical solution provided by the present invention will be further described in detail below with reference to the drawings. Specifically;

[0040] Embodiment 1. This embodiment provides a fast and high-precision swept-frequency interference measurement signal processing method, and the method includes;

[0041] Steps of separately collecting measurement signals and auxiliary signals;

[0042] Steps of roughly measuring the frequency of the measurement signal and calculating the down-conversion multiple;

[0043] Steps of modulating and filtering the measurement signal and the auxiliary signal to obtain a processed signal;

[0044] Steps of performing phase demodulation and downsampling on the auxiliary signal in the processed signal, generating a down-converted signal using the down-conversion multiple, and performing down-conversion processing on the processed measurement signal;

[0045] Steps of downsampling the phase of the auxiliary signal and the measurement signal in the processed signal;

[0046] Steps of performing non-linear correction on the down-converted signal and obtaining the absolute distance of the target through spectral analysis.

[0047] Specifically, the technical solution provided in this embodiment includes;

[0048] Step 1: Signal reception

[0049] Brief description: Use a balanced detector to receive measurement signals and auxiliary signals.

[0050] Detailed description:

[0051] Measurement signal i m (t) and auxiliary signal i f (t) are received by the balanced detector.

[0052] Step 2: Rough frequency measurement and down-conversion multiple calculation

[0053] Brief description: Roughly measure the frequency of the measurement signal and calculate the required down-conversion multiple.

[0054] Detailed description:

[0055] Roughly measure the frequency of the received measurement signal, and the methods include but are not limited to "taking partial points for FFT" or "performing FFT by channel".

[0056] Through rough frequency measurement, obtain the rough frequency value of the measurement interferometer signal

[0057] Using the known frequency f of the auxiliary signal f , calculate the down-conversion multiple m.

[0058] Step 3: Signal modulation and filtering

[0059] Brief description: Generate a modulation signal and perform modulation and filtering processing on the measurement signal and the auxiliary signal.

[0060] Detailed description:

[0061] The computer-generated modulation signal i s (t) = exp(j2πf s t), where f s is the modulation signal frequency.

[0062] Multiply the measurement signal i m (t) and the auxiliary signal i f (t) by the modulation signal respectively, and perform filtering to obtain i ms (t) and i fs (t);

[0063] Step 4: Phase demodulation and downsampling processing

[0064] Brief description: Perform phase demodulation and downsampling on the auxiliary signal, generate a downsampled signal using the downsampling multiple, and perform downsampling processing on the processed measurement signal using the downsampled signal.

[0065] Detailed description:

[0066] Perform phase demodulation and downsampling on i fs (t) to obtain its phase

[0067] Use the downsampling multiple m and generate a downsampled signal i fm (t);

[0068] Downsample and multiply i ms (t) and i fm (t) to obtain the downsampled result i' m (t);

[0069] Step 5: Nonlinear correction and spectrum analysis

[0070] Brief description: Use the correction phase to perform nonlinear correction on the downsampled signal, and obtain the absolute distance of the target through spectrum analysis.

[0071] Detailed description:

[0072] Use to generate a correction phase

[0073] Use the correction phase to perform nonlinear correction on the real part of i' m (t) to obtain the corrected signal i' m (k);

[0074] Perform spectrum analysis on the corrected signal i' m (k) and calculate the frequency f of the signalm and perform up - frequency processing on this frequency to obtain the absolute distance R of the target to be measured m .

[0075] Embodiment 2: This embodiment further limits the fast and high - precision swept - frequency interference measurement signal processing method provided in Embodiment 1. The frequency of the measurement interferometer signal is roughly measured by taking a partial number of points for Fourier transform or performing Fourier transform on separate channels

[0076] Embodiment 3: This embodiment further limits the fast and high - precision swept - frequency interference measurement signal processing method provided in Embodiment 1. A modulation signal is generated by a computer, and the modulation signal is multiplied with the measurement signal and the auxiliary signal respectively, and then filtering processing is performed

[0077] Embodiment 4: This embodiment further limits the fast and high - precision swept - frequency interference measurement signal processing method provided in Embodiment 1. The processed signal is phase - demodulated and down - sampled to obtain its phase. Combining the down - frequency multiple, a down - frequency signal is generated, and the processed signal is down - frequencyed through the down - frequency signal

[0078] Embodiment 5: This embodiment further limits the fast and high - precision swept - frequency interference measurement signal processing method provided in Embodiment 1. Non - linear correction is performed on the real part of the down - frequencyed signal according to the corrected phase

[0079] Embodiment 6: This embodiment further limits the fast and high - precision swept - frequency interference measurement signal processing method provided in Embodiment 1. Spectrum analysis is performed on the signal after non - linear correction to obtain the signal frequency, and the signal frequency is up - frequencyed to obtain the absolute distance of the target to be measured

[0080] Embodiment 7: This embodiment provides a fast and high - precision swept - frequency interference measurement signal processing device, and the device includes;

[0081] Modules for separately collecting measurement signals and auxiliary signals;

[0082] Modules for roughly measuring the frequency of the measurement signal;

[0083] Modules for modulating and filtering the measurement signal and the auxiliary signal to obtain the processed signal;

[0084] Modules for phase - demodulating and down - sampling the auxiliary signal in the processed signal, generating a down - frequency signal using the down - frequency multiple, and down - frequencying the measurement signal in the processed signal;

[0085] Modules for performing non - linear correction on the down - frequencyed signal and obtaining the absolute distance of the target through spectrum analysis

[0086] Embodiment 8. This embodiment provides a computer storage medium for storing a computer program. When the computer program is read by a computer, the computer executes the method provided in Embodiment 1.

[0087] Embodiment 9. This embodiment provides a computer, including a processor and a storage medium. When the processor reads the computer program stored in the storage medium, the computer executes the method provided in Embodiment 1.

[0088] Embodiment 10. This embodiment provides a computer program product, including a computer program. When the computer program is executed by a processor, the method provided in Embodiment 1 is implemented.

[0089] Embodiment 11. In combination with Figures 1-4 describing this embodiment, this embodiment further describes the above-provided technical solution in detail through specific examples. Specifically;

[0090] In the existing non-linear correction process, there are problems of low efficiency, which also exist in the spectrum analysis process of non-linear correction signals. Currently, this process usually uses a method composed of FFT (Fast Fourier Transform) + CZT (Chirp Z-Transform) to solve the frequency of the measurement signal, and then realizes the measurement of the target distance. However, the above spectrum analysis method has the disadvantages that the algorithm itself is complex to implement, resulting in a large number of points and a large amount of calculation, causing the measurement efficiency to decline and the fast measurement ability of the measurement system to be limited.

[0091] To solve the technical problems existing in the prior art, this embodiment proposes a fast and high-precision swept-frequency interference measurement signal processing method.

[0092] Specifically;

[0093] Figure 1 The optical path structure diagram of the swept-frequency interference measurement device adopted in this embodiment is shown. The optical path structure is mainly composed of an auxiliary interferometer (red frame ①) and a measurement interferometer (red frame ②). First, the light emitted from the swept-frequency laser passes through coupler 1, where 99% of the laser enters the measurement interferometer and 1% of the laser enters the auxiliary interferometer.

[0094] 99% of the laser light is divided by the coupler 2 into the measurement light and the reference light of the measurement interferometer. The measurement light enters the port I of the circulator, then enters the optical transmitting and receiving system from the port II of the circulator and is emitted onto the target surface. After being reflected by the target surface, the retroreflected light enters the port II of the circulator through the optical transmitting and receiving system, and is emitted from the port III of the circulator and combined with the reference light at the coupler 5 to form an interference signal. This interference signal is collected by the balanced detector B. At this time, the target optical path information is contained in the signal frequency and can be extracted through spectrum analysis.

[0095] 1% of the laser light entering the auxiliary interferometer is divided by the coupler 3 into the measurement light and the reference light of the auxiliary interferometer. The measurement light and the reference light respectively pass through the measurement arm and the reference arm and are combined at the coupler 4 to form an auxiliary interference signal. This auxiliary signal is collected by the balanced detector A, and the nonlinear correction of the measurement signal can be realized through the auxiliary signal.

[0096] As Figure 2 shown, the method based on the swept-frequency interference measurement device includes the following steps;

[0097] Step 1: The measurement signal i m (t) and the auxiliary signal i f (t) are received by the balanced detector.

[0098] Step 2: Coarse measurement of the frequency of the measurement signal obtained in Step 1 to obtain the coarse measurement value of the target frequency Using the known auxiliary signal frequency f f The down-conversion multiple m required to reduce the measurement signal frequency to f o can be calculated.

[0099] Step 3: The computer generates the modulation signal i s (t), multiplies the i m (t) and i f (t) obtained in Step 1 with the modulation signal respectively, and filters the multiplication result to obtain i ms (t) and i fs (t).

[0100] Step 4: First, perform phase demodulation and downsampling on the i fs (t) obtained in Step 3 to obtain its phase Using the down-conversion multiple m obtained in Step 2 and The down-conversion signal i fm (t) for down-converting the measurement signal can be generated, and the i ms (t) and i fm (t) obtained in Step 3 are downsampled and multiplied to obtain the down-converted result i′ m (t).

[0101] Step 5: Using the result obtained in Step 4 Generate a calibration phase Utilize the calibration phase For the i' m (t) (real part) obtained in step 4, perform non - linear calibration to obtain the calibrated signal i' m (k). Perform spectrum analysis on the signal i' m (k) and calculate the frequency f of the signal i' m (k). Perform up - frequency processing on this frequency to obtain the absolute distance R of the target to be measured m . m .

[0102] Preferably, step 1 is specifically as follows:

[0103] The balanced detector receives the measurement signal i m (t) and the auxiliary signal i f (t). The mathematical expressions of the two signals are:

[0104]

[0105] where A m and A f are the amplitudes of the measurement signal and the auxiliary signal respectively, f(t) is the optical frequency quantity under the influence of swept - frequency non - linearity, L m and L f are the optical paths of the measurement interferometer and the auxiliary interferometer respectively, and c is the speed of light.

[0106] Preferably, step 2 is specifically as follows:

[0107] Coarsely measure the frequency of the measurement interferometer signal obtained in step 1. The method of this frequency coarse measurement can be, but is not limited to, fast frequency coarse measurement methods such as "taking partial points for FFT", "performing FFT on sub - channels", etc. (In this patent, the method of "performing FFT on sub - channels" is taken as an example. The signal channelization process is as shown in the attached figure part Figure 3 in the upper figure, Figure 3 the middle figure and Figure 3 the lower figure are the time - domain and frequency - domain curves of the channelized signal). After the frequency coarse measurement, the coarsely measured frequency value of the measurement signal can be obtained Utilize the known auxiliary signal frequency f f to calculate the down - frequency multiple m required to reduce the measurement signal frequency to f o :

[0108]

[0109] Preferably, step 3 is specifically as follows:

[0110] Generate a modulation signal i s (t) through a computer:

[0111] i s (t) = exp(j2πf s t),

[0112] where f s is the modulation signal frequency. Multiply the i m (t) and i f (t) obtained in step 1 by the modulation signal respectively, and filter the multiplication results to obtain i ms (t) and i fs (t):

[0113]

[0114] where BPF is a band - pass filter, and A ms and A fs are the amplitudes of the i ms (t) and i fs (t) signals respectively.

[0115] Preferably, step 4 is specifically as follows:

[0116] Perform phase demodulation and downsampling (the downsampling factor can be selected as 4 - 5 times the down - conversion frequency f fs ) on the i o (t) obtained in step 3 to obtain its phase

[0117]

[0118] Use the down - conversion factor m obtained in step 2 and to generate a down - conversion signal i fm (t) for realizing the down - conversion of the measurement signal:

[0119]

[0120] Perform downsampling (the downsampling factor can be selected as 4 - 5 times the down - conversion frequency f ms (t) and multiply it with i fm (t) obtained in step 3 to obtain the down - converted result i' o ) on the i m (t):

[0121]

[0122] Preferably, step 5 is specifically as follows:

[0123] Use the obtained in step 4 to generate a correction phase

[0124]

[0125] Using the calibration phase For the i′ obtained in step 4 m (t) (real part) is non-linearly corrected to obtain the corrected signal i′ m (k):

[0126]

[0127] For the signal i′ m (k), spectrum analysis is performed. The spectrum analysis method can adopt but is not limited to fast spectrum analysis methods such as the all-phase time-shift phase difference spectrum analysis method combined with channelization processing. After spectrum analysis, the frequency f of the signal i′ m (k) can be calculated. By performing up-conversion processing on this frequency, the absolute distance R of the target to be measured can be obtained m :[[]]END]] m :[[]]END]]

[0128]

[0129] Figure 3 It is the principle and simulation schematic diagram of data channelization.[[]]END]]

[0130] Figure 4 It is the simulation measurement spectrum after adopting the method of this embodiment. The deviation between the measured value and the true value is at the nanometer level. Compared with the traditional method, in the case of the same measurement range, when applying this embodiment, the measurement speed is significantly improved.[[]]END]]

[0131] The method of phase demodulation and down-conversion proposed in this embodiment significantly reduces the number of processing points compared with the traditional method to improve the signal processing efficiency. At the same time, in the processing flow, combining sub-channel processing and the all-phase FFT spectrum analysis method realizes the improvement of processing efficiency from the perspective of reducing complexity. Through the above measures, this embodiment has higher processing efficiency than the previous processing methods and can quickly and accurately realize the processing of swept-frequency interference measurement signals.[[]]END]]

[0132] The above further describes the technical solutions provided by the present invention through several specific embodiments to highlight the advantages and beneficial effects of the technical solutions provided by the present invention. However, the above-mentioned several specific embodiments are not used as limitations on the present invention. Any reasonable modifications and improvements, combinations of embodiments, and equivalent replacements based on the spirit and principles of the present invention should be included within the protection scope of the present invention.[[]]END]]

Claims

1. A fast and high-precision swept frequency interferometry measurement signal processing method, characterized in that: The method comprises: The steps of collecting the measurement signal and the auxiliary signal respectively; The steps of roughly measuring the frequency of the measurement signal and solving the frequency reduction multiple; The measured signal and the auxiliary signal are modulated and filtered to obtain the processed signal i ms (t), i fs (t) steps; The steps of performing phase demodulation on the auxiliary signal in the processed signal, generating a down-frequency signal using the down-frequency multiple, and performing down-frequency processing on the measurement signal using the down-frequency signal; Among them, for i fs (t) First perform phase demodulation and downsample to obtain its phase Among them, L f is the optical path of the auxiliary interferometer, c is the speed of light, f(t) is the optical frequency under the influence of the frequency sweep nonlinearity, and f s is the modulation signal frequency, By reducing the frequency multiple m and A down-conversion signal can be generated to reduce the frequency of the measurement signal. fm (t): A step of downsampling the phase of the auxiliary signal and the measurement signal in the processed signal; The step of performing nonlinear correction on the down-converted signal and obtaining the absolute distance of the target through spectrum analysis.

2. The fast and high-precision swept frequency interferometry measurement signal processing method according to claim 1, characterized in that: The frequency of the measurement signal is roughly measured by taking a part of the points to perform Fourier transform or performing Fourier transform in different channels.

3. The fast and high-precision swept frequency interferometry measurement signal processing method according to claim 1, characterized in that: A modulation signal is generated by a computer, and the modulation signal is multiplied with the measurement signal and the auxiliary signal respectively, and then filtered.

4. The fast and high-precision swept frequency interferometry signal processing method according to claim 1, characterized in that: The auxiliary signal of the processed signal is phase-demodulated and down-sampled to obtain its phase, and a down-frequency signal is generated in combination with the down-frequency multiple, and the processed measurement signal is down-frequencyed by the down-frequency signal.

5. The fast and high-precision swept frequency interferometry measurement signal processing method according to claim 1, characterized in that: A nonlinear correction is performed on the real part of the down-converted signal according to the correction phase.

6. The fast and high-precision swept frequency interferometry measurement signal processing method according to claim 1, characterized in that: The signal after nonlinear correction is subjected to spectrum analysis to obtain the signal frequency, and the signal frequency is subjected to frequency up-conversion processing, and the absolute distance of the target to be measured can be obtained through calculation.

7. Fast and high-precision swept frequency interferometry signal processing device, characterized in that: The device comprises: Modules for collecting measurement signals and auxiliary signals respectively; A module for roughly measuring the frequency of the measurement signal; A module for performing modulation and filtering on the measurement signal and the auxiliary signal to obtain the processed signal; A module for performing phase demodulation and downsampling on the auxiliary signal in the processed signal, generating a down-frequency signal using a frequency reduction multiple, and performing frequency reduction processing on the measurement signal in the processed signal; Among them, for i fs (t) First perform phase demodulation and downsample to obtain its phase Among them, L f is the optical path of the auxiliary interferometer, c is the speed of light, f(t) is the optical frequency under the influence of the frequency sweep nonlinearity, and f s is the modulation signal frequency, By reducing the frequency multiple m and A down-conversion signal can be generated to reduce the frequency of the measurement signal. fm (t): A module that performs nonlinear correction on the down-converted signal and obtains the absolute distance of the target through spectrum analysis.

8. A computer storage medium for storing a computer program, characterized in that: When the computer program is read by a computer, the computer executes the method of claim 1 .

9. A computer, comprising a processor and a storage medium, characterized in that: When the processor reads the computer program stored in the storage medium, the computer executes the method of claim 1 .

10. Computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method of claim 1 is implemented.

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