Carrier phase delay compensation method and system based on single-chip microcomputer control

Abstract

The invention provides a carrier phase delay compensation method and system based on single-chip microcomputer control, and relates to the technical field of laser interference measurement, and the method comprises the steps: determining an interference signal based on the basic principle of a Michelson interferometer; decomposing the interference signal through a Bessel identical equation and a trigonometric function formula to obtain a target interference signal; a direct current component in the target interference signal is filtered out through an alternating current coupling sampling mode; performing frequency mixing processing and low-pass filtering processing on the target interference signal after the direct-current component is filtered out to obtain an orthogonal interference signal pair; constructing a Lissajous figure according to the orthogonal interference signal pair; judging whether carrier phase delay exists or not according to the Lissajous figure; if yes, a first control signal is output through the single-chip microcomputer, the signal generator is controlled to adjust the compensation phase and conduct stepping frequency sweeping till a first high-frequency carrier signal and a second high-frequency carrier signal output by the signal generator at the modulation end and the demodulation end are the same, and carrier phase delay is compensated.

Description

Technical Field

[0001] The invention relates to the technical field of laser interferometry, and in particular to a carrier phase delay compensation method and system based on single chip microcomputer control. Background Art

[0002] With the development of industry and science and technology, micro-vibration measurement technology is increasingly used in precision machinery, earthquake monitoring, biomedicine and other fields. Laser interferometry measurement technology, represented by Michelson interferometer, has become one of the key means of measuring micro-vibration due to its high precision and non-contact measurement characteristics. Among them, sinusoidal phase modulation interferometer is widely used in micro-vibration measurement due to its high resolution.

[0003] In the prior art, the phase generation carrier demodulation algorithm is usually used for signal demodulation of laser sinusoidal phase modulation interferometer due to its advantages of high sensitivity, strong resistance to low-frequency interference and large dynamic range. The phase generation carrier demodulation algorithm mainly includes two types: differential cross multiplication algorithm and inverse tangent algorithm, which are widely used in signal processing to obtain high-precision measurement results.

[0004] However, the generated carrier demodulation algorithm is easily affected by the phase modulation depth and carrier phase delay in practical applications, resulting in nonlinear errors and harmonic distortion.

[0005] In addition, the carrier phase delay will drift with the changes of unstable factors in the environment, which makes it difficult to maintain the accuracy of signal demodulation, thus affecting the accuracy of micro-vibration measurement. Summary of the invention

[0006] In order to solve the technical problem that the existing generated carrier demodulation algorithm is easily affected by the phase modulation depth and carrier phase delay in practical applications, resulting in nonlinear errors and harmonic distortion, and the carrier phase delay will also drift with the changes of unstable factors in the environment, which makes it difficult to maintain the accuracy of signal demodulation, thereby affecting the accuracy of micro-vibration measurement, the present invention provides a carrier phase delay compensation method and system based on single-chip microcomputer control.

[0007] The technical solution provided by the embodiment of the present invention is as follows:

[0008] First aspect:

[0009] An embodiment of the present invention provides a carrier phase delay compensation method based on single chip microcomputer control, comprising:

[0010] S1: Based on the basic principle of Michelson interferometer, determine the interference signal of the object to be measured;

[0011] S2: Decomposing the interference signal by using Bessel's identity and trigonometric function formula to obtain a target interference signal;

[0012] S3: filtering out the DC component in the target interference signal by AC coupling sampling;

[0013] S4: performing frequency mixing and low-pass filtering on the target interference signal after the DC component is filtered out to obtain an orthogonal interference signal pair;

[0014] S5: constructing a Lissajous figure according to the orthogonal interference signal pair;

[0015] S6: judging whether there is a carrier phase delay according to the Lissajous figure; if so, proceeding to the next step; otherwise, no carrier phase delay compensation is required;

[0016] S7: Outputting a first control signal through the single chip microcomputer controls the signal generator to adjust the compensation phase and perform step frequency sweep until the first high-frequency carrier signal and the second high-frequency carrier signal outputted by the signal generator at the modulation end and the demodulation end respectively are the same, so as to compensate for the carrier phase delay.

[0017] Second aspect:

[0018] A carrier phase delay compensation system based on single chip microcomputer control provided by an embodiment of the present invention includes: a memory and one or more processors;

[0019] One or more application programs are stored in the memory, and the one or more application programs are suitable for being executed by the one or more processors to implement the above-mentioned carrier phase delay compensation method based on single-chip microcomputer control.

[0020] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0021] In the present invention, the interference signal is decomposed by Bessel's identity and trigonometric function formulas to obtain a target interference signal. The DC component in the target interference signal is filtered out by an AC coupling sampling method, and the target interference signal after the DC component is filtered out is mixed and low-pass filtered to obtain an orthogonal interference signal pair. In practical applications, it is not easily affected by the phase modulation depth and carrier phase delay, and nonlinear errors and harmonic distortions are avoided. The first control signal is output by a single-chip microcomputer to control a signal generator to adjust the compensation phase and perform step frequency sweeping, thereby avoiding the phenomenon that the carrier phase delay will drift with the change of unstable factors in the environment. This maintains the accuracy of signal demodulation, thereby improving the accuracy of micro-vibration measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work.

[0023] Figure 1 A schematic flow chart of a carrier phase delay compensation method based on single chip microcomputer control provided in an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of a working principle based on single chip microcomputer control provided by an embodiment of the present invention;

[0025] Figure 3 A structural schematic diagram of a carrier phase delay compensation system based on single-chip microcomputer control provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0027] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0028] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0029] Reference Manual Attached Figure 1 , shows a flow chart of a carrier phase delay compensation method based on single chip microcomputer control provided in an embodiment of the present invention.

[0030] The embodiment of the present invention provides a carrier phase delay compensation method based on single-chip microcomputer control, which can be implemented by a carrier phase delay compensation device based on single-chip microcomputer control, and the carrier phase delay compensation device based on single-chip microcomputer control can be a terminal or a server. The processing flow of the carrier phase delay compensation method based on single-chip microcomputer control can include the following steps:

[0031] S1: Based on the basic principle of Michelson interferometer, determine the interference signal of the object to be measured.

[0032] It should be noted that the basic principle of the Michelson interferometer is as follows: the laser beam emitted by the laser first passes through a polarizer and a quarter wave plate before entering a spectroscope. The spectroscope divides the laser into two paths, one as the measurement light and the other as the reference light, and the two lasers are perpendicular to each other. After the measurement light is irradiated onto the solid surface to be measured, the solid surface produces tiny vibrations under the excitation of the speaker vibration, thereby modulating the phase of the measurement light, and then the measurement light returns to the spectroscope. The reference light is modulated into a high-frequency carrier signal by a laser phase modulator and returns to the spectroscope through a reflector. The two light paths reunite at the spectroscope, optical mixing occurs, and interference occurs, which is used to detect micro-vibration information.

[0033] Among them, the setting of the polarizer and the 1 / 4 wave plate can effectively prevent the reflected return light from entering the laser, thereby avoiding the laser power fluctuation caused by the return light.

[0034] In a possible implementation manner, S1 specifically includes:

[0035] According to the following formula, the interference signal of the object to be measured is determined:

[0036] S(t)=A 0 +A 1 cos[Ccos(ω c t)+ψ(t)]

[0037] Among them, S(t) represents the interference signal of the object to be measured at time t, t represents the time, A 0 Represents the amplitude of the DC component related to light intensity, A 1 represents the amplitude of the AC component related to the optical power intensity of the reference light and the measurement light, cos represents the cosine function, C represents the phase modulation depth, ω c represents the phase modulation depth carrier frequency, and ψ(t) represents the phase to be measured at time t.

[0038] The phase to be measured is specifically:

[0039] ψ(t)=2kX l sin(ω l t+ψ l )+ψ(0)

[0040] Where k represents the wave number, X l represents the amplitude of the interference signal disturbance, sin represents the sine function, ω l represents the angular frequency of the interference signal disturbance, ψ l represents the initial phase of the interference signal disturbance, and ψ(0) represents the phase difference caused by the initial optical path difference between the reference arm and the measurement arm.

[0041] In the present invention, by using the basic principle of Michelson interferometer and the interference effect of laser beam, tiny vibrations can be measured with high precision. By interfering the measurement light with the reference light, the change of interference fringes is closely related to the phase change of the surface vibration of the object. By accurately capturing these phase changes, the interference caused by system noise or environmental changes can be eliminated, thereby obtaining reliable vibration measurement results. By decomposing the signal and using the phase modulation depth and interference signal perturbation model (parameters such as amplitude, frequency, initial phase, etc. shown in the formula), the target signal can be extracted more accurately, thereby effectively distinguishing the micro-vibration signal from other noise or interference signals. Through this method, the signal components related to the target vibration can be accurately captured to ensure the sensitivity of the system to the target signal.

[0042] S2: Decompose the interference signal through Bessel's identity and trigonometric function formula to obtain the target interference signal.

[0043] It should be noted that Bessel identities are a type of mathematical relationship related to Bessel functions. Bessel functions are functions that solve a type of partial differential equations, and are often used to describe circularly symmetric problems, such as physical phenomena such as vibration and heat conduction. Bessel identities usually include addition, multiplication, or other types of relationships between Bessel functions, which provide mathematical tools for signal processing to decompose complex signals. For example, Bessel functions can be used to represent the components of periodic signals, so that when processing interference signals, the frequency components of the signal can be decomposed to facilitate subsequent analysis and filtering.

[0044] It should be noted that trigonometric formulas refer to mathematical formulas related to trigonometric functions such as sine (sin), cosine (cos), and tangent (tan). These formulas are used to simplify and transform the expressions of trigonometric functions, and common ones include the sum angle formula, the double angle formula, the addition theorem, etc. They are very important in signal analysis, especially when dealing with periodic waveforms, which can help break down complex waveforms into simpler components. Through these formulas, the complex oscillation part of the interference signal can be decomposed and its components of different frequencies and amplitudes can be extracted, thereby achieving effective signal analysis and processing.

[0045] In a possible implementation manner, S2 is specifically:

[0046] According to the following formula, the interference signal is decomposed through Bessel's identity and trigonometric function formula to obtain the target interference signal:

[0047]

[0048] in, represents the target interference signal at time t, J 0 represents the 0th order Bessel function, α represents the order of the Bessel function, J2α represents the 2α-order Bessel function, J 2α-1 represents the 2α-1 order Bessel function.

[0049] In the present invention, the interference signal is usually composed of multiple frequency components superimposed, and may contain sine waves, cosine waves and other complex oscillation components. Bessel functions and trigonometric function formulas can effectively decompose complex signals into simpler periodic components. This decomposition process enables us to accurately extract the various components in the interference signal, which is convenient for subsequent analysis and processing. By combining the Bessel identity and trigonometric function formulas, complex signal expressions can be converted into more easily processable mathematical forms. This makes subsequent analysis and calculations more efficient. In particular, when processing interference signals, the main frequency components of the signal can be quickly identified and noise and irrelevant signal components can be removed.

[0050] S3: Filter out the DC component in the target interference signal through AC coupling sampling.

[0051] It should be noted that AC coupling sampling is a signal processing technology that is mainly used to filter out the DC component in the signal. The DC component refers to the part of the signal that does not change with time, usually the average value of the signal, while the AC signal is the part that fluctuates with time. In the AC coupling sampling method, the signal is connected to the subsequent circuit through a capacitor, which can block the DC component and allow the AC signal to pass. This method allows subsequent processing to focus more on the changing part of the signal (i.e. the AC part), thereby improving the accuracy of signal analysis, especially when analyzing periodic signals (such as interference signals), removing the DC component can avoid its interference with subsequent processing.

[0052] In the present invention, the DC component is the part of the signal that does not change with time, and usually represents the average value of the signal. Since the DC component does not carry any useful periodic change information, it has no practical significance for analyzing periodic signals. By filtering out the DC component, inaccurate analysis results caused by interference from the DC part in subsequent processing can be avoided. By removing the DC component, the effective AC component of the signal will be more prominent, especially in the analysis of periodic signals, the accuracy of signal analysis can be improved.

[0053] S4: performing frequency mixing and low-pass filtering on the target interference signal after the DC component is filtered out to obtain an orthogonal interference signal pair.

[0054] It should be noted that frequency mixing is a signal processing technique that generates new frequency components by multiplying (mixing) two signals of different frequencies. In interference signal processing, frequency mixing is usually used to convert high-frequency signals into lower-frequency signals that are easier to process. Specifically, by mixing the interference signal with a carrier signal of a reference frequency, a low-frequency component (baseband signal) containing the signal frequency can be obtained. This method is often used to demodulate and extract useful information from signals, especially in the fields of wireless communications and signal processing.

[0055] It should be noted that low-pass filtering is a filtering technology used to remove the signal components above a certain frequency and retain only the signal components below the frequency. The low-pass filter allows signals with frequencies below the cutoff frequency to pass through, while attenuating or completely filtering out components above the frequency. In interference signal processing, low-pass filtering is usually used to remove high-frequency noise generated after mixing and retain only the low-frequency part of the target signal, thereby improving the quality and resolvability of the signal.

[0056] Optionally, the orthogonal interference signal pair is specifically:

[0057]

[0058] Where Q(t) represents the sinusoidal component of the orthogonal interference signal pair at time t, E 1 represents the filter gain coefficient of the sinusoidal component of the orthogonal interference signal pair, J 1 represents the first-order Bessel function, Δθ represents the carrier phase delay, I(t) represents the cosine component of the orthogonal interference signal pair at time t, E 2 represents the filter gain coefficient of the cosine component of the orthogonal interference signal pair, J 2 represents the second-order Bessel function.

[0059] In the present invention, the main purpose of the mixing process is to convert the high-frequency signal into a low-frequency signal that is easier to process. By mixing the interference signal with the carrier signal of the reference frequency, the high-frequency signal can be converted into a low-frequency baseband signal, so that the useful information in the signal can be more easily extracted and analyzed. In the interference signal processing, the mixed signal often contains some unnecessary high-frequency noise components, which may affect the quality and accuracy of the signal. Through low-pass filtering, these high-frequency noises can be effectively removed, and only the low-frequency part of the target signal is retained, thereby improving the quality and resolvability of the signal.

[0060] Optionally, the filter gain coefficient E for the sinusoidal component of the orthogonal interference signal pair is 1 , the filter gain coefficient E of the cosine component of the orthogonal interference signal pair 2 And the amplitude A of the AC component related to the optical power intensity of the reference light and the measurement light 1, and eliminate its influence on the demodulation process by signal normalization. Specifically, by normalizing the orthogonal interference signal pair, the amplitude of the signal is independent of the above parameters in the calculation, thereby ensuring the accuracy and stability of the signal demodulation result without the need to accurately solve E 1 、E 2 and A 1 The actual value of .

[0061] Optionally, the phase modulation depth C is processed by combining the fast Fourier transform (FFT) and proportional-integral-differential (PID) control method. First, the frequency spectrum of the interference signal is analyzed by the FFT algorithm to preliminarily estimate the value of the phase modulation depth C. Then, on this basis, a closed-loop feedback system is constructed by introducing a PID controller to dynamically adjust and optimize the estimated value of C, and finally adjust it to the target value, thereby effectively eliminating the nonlinear error and harmonic distortion caused by inaccurate phase modulation depth.

[0062] It should be noted that the Fast Fourier Transform (FFT) is an efficient algorithm for calculating the Fourier transform of a signal. The Fourier transform converts the signal in the time domain into the frequency domain, revealing the amplitude and phase of each frequency component in the signal. The FFT algorithm makes this conversion process faster and more efficient by reducing the computational complexity, and is particularly suitable for spectral analysis of large-scale data. In signal processing, FFT can help analyze the frequency distribution in interference signals, thereby estimating and extracting information related to the phase modulation depth.

[0063] It should be noted that the PID controller is a classic control algorithm that combines three parts: proportional (P), integral (I) and differential (D) to control the output of the system to achieve the desired target value. The proportional part applies control according to the size of the error, the integral part accumulates the error to eliminate long-term deviations, and the differential part makes adjustments in advance by predicting the error change trend. Through the combination of these three mechanisms, the PID controller can achieve precise regulation and dynamic response of the system.

[0064] In the present invention, by normalizing the orthogonal interference signal pair, the amplitude of the signal can be made independent of the filter gain coefficient and the AC component amplitude, thereby reducing the influence of changes in these parameters on signal demodulation and ensuring the accuracy and stability of the signal demodulation results. Through the combination of PID control and FFT, the system can adapt to different signal changes and disturbances, maintaining good dynamic responsiveness and accuracy. The PID controller can adjust the phase modulation depth in real time, eliminate the influence of unstable factors or environmental disturbances, and keep the system stable in a complex environment.

[0065] S5: Construct Lissajous figures based on the orthogonal interference signal pairs.

[0066] It should be noted that the Lissajous curve is a curve drawn on a plane by two orthogonal (mutually perpendicular) signals, and is often used to show the relative frequency and phase relationship between signals. Specifically, when two signals change along the x-axis and y-axis respectively, the trajectory formed by their interaction is the Lissajous curve. This type of graph is usually used to represent the relationship between the phase difference and frequency ratio of two periodic signals. For example, when the frequency ratio of two sine waves is an integer, the Lissajous curve appears as a regular geometric shape, such as an ellipse, a circle, a biloba, etc. Lissajous curves can intuitively reflect the synchronization and phase difference of the signal, and are often used in signal analysis and interferometry to help determine the quality of the signal and the errors that exist.

[0067] In a possible implementation, S5 is specifically:

[0068] A Lissajous figure is constructed with the sine component of the orthogonal interference signal pair as the horizontal axis and the cosine component of the orthogonal interference signal pair as the vertical axis.

[0069] In the present invention, by constructing Lissajous figures to analyze orthogonal interference signal pairs, the relationship between the phase difference and the frequency ratio between the signals can be intuitively displayed, thereby effectively detecting the synchronization, stability and quality of the signals. Lissajous figures can reveal nonlinear errors and phase deviations in the signals, help identify and eliminate these errors, and ensure the accuracy and stability of signal demodulation. By observing the changes in the figures in real time, the phase adjustment of the signals can be optimized, the robustness of the system can be improved, and the complex signal analysis process can be simplified, and the efficiency of signal processing can be enhanced. Therefore, Lissajous figures provide an intuitive and efficient tool in interferometry for improving the accuracy, reliability and adaptability of signals.

[0070] S6: According to the Lissajous figure, determine whether there is a carrier phase delay. If so, proceed to the next step. Otherwise, there is no need to perform carrier phase delay compensation.

[0071] Specifically, according to the Lissajous figure, it is possible to determine whether there is a carrier phase delay by analyzing the shape of the Lissajous figure. When the carrier phase delay is zero, the Lissajous figure of the orthogonal interference signal pair is a standard circle. When there is a carrier phase delay, the Lissajous figure will undergo an elliptical deformation, which manifests as stretching or compression along a certain direction. Furthermore, it is possible to confirm whether there is a carrier phase delay by calculating whether the normalized maximum value of the Lissajous figure in the horizontal and vertical coordinate directions is equal to 1 at the same time. If the normalized maximum value does not meet this condition, it indicates that there is a carrier phase delay and compensation is required. If the normalized maximum value is 1 at the same time, no compensation is required.

[0072] In the present invention, by analyzing the shape of the Lissajous figure to determine whether there is a carrier phase delay, the phase error can be detected quickly and intuitively. By observing the changes in the Lissajous figure, when the carrier phase delay is zero, the figure is circular. When there is a phase delay, the figure becomes elliptical. Furthermore, the inspection of the normalized maximum value can effectively confirm whether compensation is required, thereby avoiding unnecessary calculations and operations and improving efficiency. This method can accurately identify and compensate for phase delays, ensure the accuracy and stability of signal demodulation, save computing resources, and improve the automation and real-time feedback capabilities of the system. In addition, through the monitoring of the Lissajous figure, the system can flexibly adjust and optimize the phase compensation, thereby enhancing the robustness of the system in complex environments.

[0073] Reference Manual Attached Figure 2 , showing a schematic diagram of a working principle based on single chip microcomputer control provided by an embodiment of the present invention.

[0074] S7: Outputting a first control signal through the single chip microcomputer controls the signal generator to adjust the compensation phase and perform step frequency sweep until the first high-frequency carrier signal and the second high-frequency carrier signal outputted by the signal generator at the modulation end and the demodulation end respectively are the same, so as to compensate for the carrier phase delay.

[0075] Specifically, the single chip microcomputer outputs a first control signal to control the signal generator, and the compensation phase θ com = 0, and perform step frequency sweep with a phase division of 0.1, continuously increasing the carrier phase delay Δθ until Δθ+θ com = 0. At this time, the first high-frequency carrier signal and the second high-frequency carrier signal outputted by the signal generator at the modulation end and the demodulation end are the same [S md (t) = S dm (t), A md cos(ω c t+0)=A dm cos(ω c t)].

[0076] It should be noted that when the first high-frequency carrier signal is the same as the second high-frequency carrier signal, the phase difference between the first high-frequency carrier signal and the second high-frequency carrier signal is eliminated. At this time, the normalized maximum values ​​of the Lissajous figure of the orthogonal interference signal pair in the horizontal and vertical directions must be achieved and simultaneously achieve the maximum value of 1, that is, the optimization goal is achieved (the normalized maximum values ​​of the Lissajous figure of the orthogonal interference signal pair in the horizontal and vertical directions simultaneously achieve the maximum value of 1), so that the carrier phase delay is compensated.

[0077] It should be noted that the two channels of the signal generator are respectively connected to the laser phase modulator at the modulation end and the signal acquisition card at the demodulation end.

[0078] In the present invention, a single-chip microcomputer is used to control a signal generator to perform step-by-step frequency sweep adjustment to accurately compensate for carrier phase delay, ensure that the high-frequency carrier signals at the modulation end and the demodulation end are the same, thereby eliminating the phase difference and optimizing signal demodulation. This process can automatically detect and compensate for phase delay, ensuring the accuracy and stability of signal demodulation. When the carrier phase delay is eliminated, the Lissajous figure of the orthogonal interference signal pair will reach a normalized maximum value of 1 in the horizontal and vertical coordinate directions, indicating that the system has reached the optimal state. Through an automated control method, the method simplifies the signal compensation process, improves the system's adaptability, stability and measurement accuracy, while reducing manual intervention and improving operating efficiency.

[0079] Optionally, the first high-frequency carrier signal is specifically:

[0080] S md (t) = A md cos(ω c t+Δθ+θ com )

[0081] Among them, S md (t) represents the actual modulated carrier signal at time t, i.e., the first high-frequency carrier signal, A md represents the amplitude of the first high-frequency carrier signal, θ com Indicates the compensation phase for frequency sweep.

[0082] Optionally, the second high-frequency carrier signal is specifically:

[0083] S dm (t) = A dm cos(ω c t)

[0084] Among them, S dm (t) represents the carrier signal used for demodulation at time t, i.e., the second high-frequency carrier signal, A dm Indicates the amplitude of the second high-frequency carrier signal.

[0085] In the present invention, by designing the first and second high-frequency carrier signals respectively and controlling their amplitude and compensation phase, the modulation and demodulation processes can be accurately adjusted to ensure the synchronization and accuracy of the signals. The independent control of the compensation phase and amplitude enables the system to flexibly adapt to different working conditions and effectively eliminate the error caused by phase delay, thereby improving the accuracy of signal demodulation.

[0086] In a possible implementation manner, after S7, the method further includes:

[0087] S8: When the first high-frequency carrier signal is the same as the second high-frequency carrier signal, the second control signal is output through the single-chip microcomputer to lock the phase of the high-frequency carrier signal output by the current signal generator at the demodulation end, the control signal generator no longer performs step frequency sweep, and sends a compensation completion signal to the computer.

[0088] Specifically, when the first high-frequency carrier signal is the same as the second high-frequency carrier signal (that is, when the optimization target is reached), the second control signal is output through the single-chip microcomputer to lock the phase of the high-frequency carrier signal output by the current signal generator at the demodulation end, and the control signal generator no longer performs step frequency sweeping, and sends a compensation completion signal to the computer, and the current compensation phase and demodulation result are recorded by the computer.

[0089] In the present invention, by stopping the step frequency sweep and locking the carrier signal phase of the demodulation end after the carrier signal phase compensation is completed, the system can ensure the synchronization of the carrier signals at the modulation end and the demodulation end, thereby eliminating the phase delay and improving the demodulation accuracy and signal stability. Stopping the frequency sweep avoids unnecessary calculations and adjustments, improves the system efficiency, and records the compensation phase and demodulation results in real time through the computer to achieve automatic control and data feedback. This method not only reduces energy consumption, but also ensures the stability and accuracy of the system in high-precision measurement, thereby optimizing the entire signal processing process and improving the automation level and operation efficiency of the system.

[0090] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0091] In the present invention, the interference signal is decomposed by Bessel's identity and trigonometric function formulas to obtain a target interference signal. The DC component in the target interference signal is filtered out by an AC coupling sampling method, and the target interference signal after the DC component is filtered out is mixed and low-pass filtered to obtain an orthogonal interference signal pair. In practical applications, it is not easily affected by the phase modulation depth and carrier phase delay, and nonlinear errors and harmonic distortions are avoided. The first control signal is output by a single-chip microcomputer to control a signal generator to adjust the compensation phase and perform step frequency sweeping, thereby avoiding the phenomenon that the carrier phase delay will drift with the change of unstable factors in the environment. This maintains the accuracy of signal demodulation, thereby improving the accuracy of micro-vibration measurement.

[0092] Reference Manual Attached Figure 3 , showing a structural schematic diagram of a carrier phase delay compensation system based on single-chip microcomputer control provided by the present invention.

[0093] The present invention further provides a carrier phase delay compensation system 30 based on single chip microcomputer control, comprising: a memory 303 and one or more processors 301 .

[0094] One or more application programs are stored in the memory 303 , and the one or more application programs are suitable for being executed by the one or more processors 301 to implement the carrier phase delay compensation method based on single-chip microcomputer control described in the method embodiment.

[0095] The carrier phase delay compensation system 30 based on single chip microcomputer control includes: a processor 301 and a memory 303. The processor 301 and the memory 303 are connected, for example, through a bus 302.

[0096] The structure of the carrier phase delay compensation system 30 based on single chip microcomputer control does not constitute a limitation to the embodiment of the present invention.

[0097] Processor 301 may be a CPU, a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of the present invention. Processor 301 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0098] The bus 302 may include a path to transmit information between the above components. The bus 302 may be a PCI bus or an EISA bus, etc. The bus 302 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0099] The memory 303 can be a ROM or other type of static storage device that can store static information and instructions, a RAM or other type of dynamic storage device that can store information and instructions, or an EEPROM, a CD-ROM or other optical disk storage, an optical disk storage (including a compressed optical disk, a laser disk, an optical disk, a digital versatile disk, a Blu-ray disk, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited to these.

[0100] It should be noted that the carrier phase delay compensation system 30 based on single-chip microcomputer control can implement the above-mentioned carrier phase delay compensation method based on single-chip microcomputer control, and can achieve the same or similar technical effects. To avoid repetition, the present invention will not go into details.

[0101] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0102] In the present invention, the interference signal is decomposed by Bessel's identity and trigonometric function formulas to obtain a target interference signal. The DC component in the target interference signal is filtered out by an AC coupling sampling method, and the target interference signal after the DC component is filtered out is mixed and low-pass filtered to obtain an orthogonal interference signal pair. In practical applications, it is not easily affected by the phase modulation depth and carrier phase delay, and nonlinear errors and harmonic distortions are avoided. The first control signal is output by a single-chip microcomputer to control a signal generator to adjust the compensation phase and perform step frequency sweeping, thereby avoiding the phenomenon that the carrier phase delay will drift with the change of unstable factors in the environment. This maintains the accuracy of signal demodulation, thereby improving the accuracy of micro-vibration measurement.

[0103] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program can be loaded and executed by a processor to implement the carrier phase delay compensation method based on single-chip microcomputer control as described in the first aspect.

[0104] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0105] There are a few points to note:

[0106] (1) The drawings of the embodiments of the present invention only relate to the structures related to the embodiments of the present invention, and other structures may refer to the general design.

[0107] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, the thickness of the layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0108] (3) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0109] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A carrier phase delay compensation method based on single chip microcomputer control, characterized in that: include: S1: Based on the basic principle of Michelson interferometer, determine the interference signal of the object to be measured; S2: Decomposing the interference signal by using Bessel's identity and trigonometric function formula to obtain a target interference signal; S3: filtering out the DC component in the target interference signal by AC coupling sampling; S4: performing frequency mixing and low-pass filtering on the target interference signal after the DC component is filtered out to obtain an orthogonal interference signal pair; S5: constructing a Lissajous figure according to the orthogonal interference signal pair; S6: judging whether there is a carrier phase delay according to the Lissajous figure; if so, proceeding to the next step; Otherwise, there is no need to perform carrier phase delay compensation; S7: Outputting a first control signal through the single chip microcomputer controls the signal generator to adjust the compensation phase and perform step frequency sweep until the first high-frequency carrier signal and the second high-frequency carrier signal outputted by the signal generator at the modulation end and the demodulation end respectively are the same, so as to compensate for the carrier phase delay.

2. The carrier phase delay compensation method based on single chip microcomputer control according to claim 1 is characterized in that: The S1 is specifically: According to the following formula, the interference signal of the object to be measured is determined: S(t)=A0+A1cos[Ccos(ω c t)+ψ(t)] Where S(t) represents the interference signal of the object to be measured at time t, t represents the time, A0 represents the amplitude of the DC component related to the light intensity, A1 represents the amplitude of the AC component related to the optical power intensity of the reference light and the measurement light, cos represents the cosine function, C represents the phase modulation depth, ω c represents the phase modulation depth carrier frequency, and ψ(t) represents the phase to be measured at time t.

3. The carrier phase delay compensation method based on single chip microcomputer control according to claim 2 is characterized in that: The phase to be measured is specifically: ψ(t)=2kX l sin(ω l t+ψ l )+ψ(0) Where k represents the wave number, X l represents the amplitude of the interference signal disturbance, sin represents the sine function, ω l represents the angular frequency of the interference signal disturbance, ψ l represents the initial phase of the interference signal disturbance, and ψ(0) represents the phase difference caused by the initial optical path difference between the reference arm and the measurement arm.

4. The carrier phase delay compensation method based on single chip microcomputer control according to claim 1 is characterized in that: The S2 is specifically: According to the following formula, the interference signal is decomposed by Bessel's identity and trigonometric function formula to obtain the target interference signal: in, represents the target interference signal at time t, J0 represents the 0th order Bessel function, α represents the order of the Bessel function, J 2α represents the 2α-order Bessel function, J 2α-1 represents the 2α-1 order Bessel function.

5. The carrier phase delay compensation method based on single chip microcomputer control according to claim 1 is characterized in that: The orthogonal interference signal pair is specifically: Among them, Q(t) represents the sinusoidal component of the orthogonal interference signal pair at time t, E1 represents the filter gain coefficient of the sinusoidal component of the orthogonal interference signal pair, J1 represents the first-order Bessel function, Δθ represents the carrier phase delay, I(t) represents the cosine component of the orthogonal interference signal pair at time t, E2 represents the filter gain coefficient of the cosine component of the orthogonal interference signal pair, and J2 represents the second-order Bessel function.

6. The carrier phase delay compensation method based on single chip microcomputer control according to claim 5 is characterized in that: The S5 is specifically: A Lissajous figure is constructed with the sine component of the orthogonal interference signal pair as the abscissa axis and the cosine component of the orthogonal interference signal pair as the ordinate axis.

7. The carrier phase delay compensation method based on single chip microcomputer control according to claim 1 is characterized in that: The first high-frequency carrier signal is specifically: S md (t)=A md cos(ω c t+Δθ+θ com ) Among them, S md (t) represents the actual modulated carrier signal at time t, i.e., the first high-frequency carrier signal, A md represents the amplitude of the first high-frequency carrier signal, θ com Indicates the compensation phase for frequency sweep.

8. The carrier phase delay compensation method based on single chip microcomputer control according to claim 1, characterized in that: The second high frequency carrier signal is specifically: S dm (t)=A dm cos(ω c t) Among them, S dm (t) represents the carrier signal used for demodulation at time t, i.e., the second high-frequency carrier signal, A dm Indicates the amplitude of the second high-frequency carrier signal.

9. The carrier phase delay compensation method based on single chip microcomputer control according to claim 1, characterized in that: After S7, the method further includes: S8: When the first high-frequency carrier signal is the same as the second high-frequency carrier signal, the single-chip microcomputer outputs a second control signal to phase-lock the high-frequency carrier signal output by the current signal generator at the demodulation end, control the signal generator to stop stepping and sweeping the frequency, and send a compensation completion signal to the computer.

10. A carrier phase delay compensation system based on single chip microcomputer control, characterized in that: include: memory and one or more processors; One or more application programs are stored in the memory, and the one or more application programs are suitable for being executed by the one or more processors to implement the carrier phase delay compensation method based on single-chip microcomputer control as described in any one of claims 1 to 9.

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