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

Abstract

The application provides a carrier phase delay compensation method and system based on single-chip microcomputer control, and relates to the technical field of laser interferometry. The method comprises the following steps: determining an interference signal based on the basic principle of a Michelson interferometer; decomposing the interference signal through Bessel identity and a trigonometric function formula to obtain a target interference signal; filtering out a direct current component in the target interference signal through an alternating coupling sampling mode; performing mixing processing and low-pass filtering processing on the target interference signal after filtering out the direct current component to obtain a pair of quadrature interference signals; constructing a Lissajous figure according to the pair of quadrature interference signals; judging whether there is carrier phase delay according to the Lissajous figure; if yes, outputting a first control signal through a single-chip microcomputer, and adjusting a compensation phase and performing step-by-step frequency sweeping through a signal generator, until a first high-frequency carrier signal and a second high-frequency carrier signal output by the signal generator at a modulation end and a demodulation end are the same, so that the carrier phase delay is compensated.

Description

Technical Field

[0001] This invention relates to the field of laser interferometry technology, and in particular to a carrier phase delay compensation method and system based on microcontroller control. Background Technology

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

[0003] In existing technologies, phase generation carrier demodulation algorithms are commonly used for signal demodulation in laser sinusoidal phase modulation interferometers due to their advantages of high sensitivity, strong resistance to low-frequency interference, and large dynamic range. Phase generation carrier demodulation algorithms mainly include two categories: differential cross-multiplication algorithms and arctangent algorithms, and are widely used in signal processing to obtain high-precision measurement results.

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

[0005] Furthermore, the carrier phase delay can drift with changes in unstable factors in the environment, making it difficult to maintain the accuracy of signal demodulation and thus affecting the accuracy of micro-vibration measurements. Summary of the Invention

[0006] To address the technical problem that existing carrier demodulation algorithms are easily affected by phase modulation depth and carrier phase delay in practical applications, leading to nonlinear errors and harmonic distortion, and that carrier phase delay can also drift with changes in unstable factors in the environment, making it difficult to maintain the accuracy of signal demodulation and thus affecting the accuracy of micro-vibration measurement, this invention provides a carrier phase delay compensation method and system based on microcontroller control.

[0007] The technical solutions provided by the embodiments of the present invention are as follows:

[0008] First aspect:

[0009] This invention provides a carrier phase delay compensation method based on microcontroller control, comprising:

[0010] S1: Based on the basic principle of the Michelson interferometer, determine the interference signal of the object under test;

[0011] S2: The interference signal is decomposed using Bessel identities and trigonometric function formulas to obtain the target interference signal;

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

[0013] S4: Perform frequency mixing and low-pass filtering on the target interference signal after removing the DC component to obtain orthogonal interference signal pairs;

[0014] S5: Construct a Lissajous figure based on the orthogonal interference signal pairs;

[0015] S6: Based on the Lissajous figure, determine whether there is a carrier phase delay; if yes, proceed to the next step; otherwise, no carrier phase delay compensation is required.

[0016] S7: The microcontroller outputs a first control signal to control 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 output by the signal generator at the modulation end and demodulation end are the same, so as to compensate for the carrier phase delay.

[0017] The second aspect:

[0018] The present invention provides a carrier phase delay compensation system based on microcontroller control, comprising: a memory and one or more processors;

[0019] The memory stores one or more application programs, which are adapted to be executed by the one or more processors to implement the above-described microcontroller-based carrier phase delay compensation method.

[0020] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0021] In this invention, the interference signal is decomposed using Bessel identities and trigonometric formulas to obtain the target interference signal. The DC component in the target interference signal is filtered out using AC coupling sampling. The DC-filtered target interference signal is then subjected to mixing and low-pass filtering to obtain an orthogonal interference signal pair. In practical applications, this is less susceptible to the effects of phase modulation depth and carrier phase delay, avoiding nonlinear errors and harmonic distortion. A first control signal is output from the microcontroller to control the signal generator to adjust the compensation phase and perform step-by-step frequency sweeping, preventing the carrier phase delay from drifting due to changes in unstable environmental factors. This maintains the accuracy of signal demodulation, thereby improving the accuracy of micro-vibration measurement. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A flowchart illustrating a carrier phase delay compensation method based on microcontroller control, provided for an embodiment of the present invention;

[0024] Figure 2 A schematic diagram illustrating the working principle of a single-chip microcomputer-based control system provided in this embodiment of the invention;

[0025] Figure 3 This is a schematic diagram of a carrier phase delay compensation system based on microcontroller control, provided for an embodiment of the present invention. Detailed Implementation

[0026] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0027] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0028] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0029] Reference manual attached Figure 1 The diagram shows a schematic flowchart of a carrier phase delay compensation method based on microcontroller control provided by an embodiment of the present invention.

[0030] This invention provides a carrier phase delay compensation method based on microcontroller control. This method can be implemented by a microcontroller-controlled carrier phase delay compensation device, which can be a terminal or a server. The processing flow of the microcontroller-controlled carrier phase delay compensation method may include the following steps:

[0031] S1: Based on the basic principle of the Michelson interferometer, determine the interference signal of the object under test.

[0032] It should be noted that the basic principle of a 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 beam splitter. The beam splitter divides the laser beam into two paths: one as the measurement beam and the other as the reference beam, with the two beams perpendicular to each other. After the measurement beam illuminates the surface of the solid being measured, the surface vibrates slightly under the excitation of a speaker, thus modulating the phase of the measurement beam, which then returns to the beam splitter. The reference beam is modulated into a high-frequency carrier signal by a laser phase modulator and returns to the beam splitter through a mirror. The two beams re-intersect at the beam splitter, undergoing optical mixing and forming an interference phenomenon used to detect micro-vibration information.

[0033] The use of polarizers and quarter-wave plates can effectively prevent reflected light from entering the laser, thereby avoiding laser power fluctuations caused by reflected light.

[0034] In one possible implementation, S1 specifically refers to:

[0035] The interference signal of the object under test is determined using the following formula:

[0036] S(t) = A0 + A1cos[Ccos(ω) c t)+ψ(t)]

[0037] Where S(t) represents the interference signal of the object under test at time t, t represents time, A0 represents the amplitude of the DC component related to light intensity, A1 represents the amplitude of the AC component related to the light power intensity of the reference light and the measurement light, cos represents the cosine function, C represents the phase modulation depth, and ω c Let ψ(t) represent the phase modulation depth carrier frequency, and let ψ(t) represent the phase to be measured at time t.

[0038] Specifically, the phase to be measured is:

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

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

[0041] In this invention, based on the fundamental principles of a Michelson interferometer, the interference effect of a laser beam enables high-precision measurement of minute vibrations. By interfering the measurement beam with a reference beam, the changes in the interference fringes are closely related to the phase changes of the object's surface vibration. By accurately capturing these phase changes, interference caused by system noise or environmental variations can be eliminated, thus obtaining reliable vibration measurement results. By decomposing the signal and using the phase modulation depth and interference signal perturbation model (such as the amplitude, frequency, and initial phase parameters shown in the formula), the target signal can be extracted more accurately, effectively distinguishing the micro-vibration signal from other noise or interference signals. This method accurately captures signal components related to the target vibration, ensuring the system's sensitivity to the target signal.

[0042] S2: The interference signal is decomposed using Bessel identities and trigonometric function formulas to obtain the target interference signal.

[0043] It's important to note that Bessel identities are a class of mathematical relationships related to Bessel functions. Bessel functions are functions that solve a class of partial differential equations, typically used to describe circularly symmetric problems, such as vibrations and heat conduction. Bessel identities usually include addition, multiplication, or other types of relationships between Bessel functions, providing mathematical tools for signal processing to decompose complex signals. For example, Bessel functions can be used to represent the components of periodic signals, thus facilitating subsequent analysis and filtering when processing interferometric signals by decomposing the signal's frequency components.

[0044] It should be noted that trigonometric function formulas refer to mathematical formulas related to trigonometric functions such as sine (sin), cosine (cosine), and tangent (tan). These formulas are used to simplify and transform the expressions of trigonometric functions, and common ones include the sum of angles formula, double-angle formula, and addition theorem. They are very important in signal analysis, especially when dealing with periodic waveforms, as they help to break down complex waveforms into simpler components. Using these formulas, the complex oscillating components in interference signals can be decomposed, and their components of different frequencies and amplitudes can be extracted, thus enabling effective signal analysis and processing.

[0045] In one possible implementation, S2 specifically refers to:

[0046] The target interference signal is obtained by decomposing the interference signal using Bessel identities and trigonometric formulas according to the following formula:

[0047]

[0048] in, Let J0 represent the target interference signal at time t, J0 represent the 0th order Bessel function, and α represent the order of the Bessel function. 2αJ represents the 2α-order Bessel function. 2α-1 This represents the 2α-1 order Bessel function.

[0049] In this invention, interference signals are typically composed of a superposition of multiple frequency components, potentially including sine waves, cosine waves, and other complex oscillating components. Bessel functions and trigonometric formulas can effectively decompose complex signals into simpler periodic components. This decomposition process allows for the precise extraction of individual components from the interference signal, facilitating subsequent analysis and processing. By combining Bessel identities and trigonometric formulas, complex signal expressions can be transformed into more manageable mathematical forms. This makes subsequent analysis and calculations more efficient. Especially when processing interference signals, it enables the rapid identification of the main frequency components and the removal of noise and irrelevant signal components.

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

[0051] It's important to note that AC-coupled sampling (AC-CMS) is a signal processing technique primarily used to filter out the DC component of a signal. The DC component refers to the portion of a signal that doesn't change over time, typically its average value, while AC signals fluctuate over time. In AC-CMS, the signal is connected to subsequent circuitry via a capacitor. This capacitor blocks the DC component while allowing the AC signal to pass through. This method allows subsequent processing to focus more on the changing portion of the signal (i.e., the AC component), thereby improving the accuracy of signal analysis. This is particularly important when analyzing periodic signals (such as interference signals), as removing the DC component prevents it from interfering with subsequent processing.

[0052] In this invention, the DC component is the portion of the signal that does not change over time, typically representing the signal's average value. Since the DC component does not carry any useful information about periodic variations, it is of no practical significance for analyzing periodic signals. By filtering out the DC component, inaccurate analysis results due to interference from the DC portion can be avoided during subsequent processing. Removing the DC component makes the effective AC component of the signal more prominent, particularly in the analysis of periodic signals, thereby improving the accuracy of signal analysis.

[0053] S4: Perform frequency mixing and low-pass filtering on the target interference signal after removing the DC component to obtain orthogonal interference signal pairs.

[0054] It's important to note that frequency mixing is a signal processing technique that produces new frequency components by multiplying (mixing) two signals of different frequencies. In interferometric signal processing, frequency mixing is typically used to convert high-frequency signals into lower-frequency signals that are easier to process. Specifically, mixing the interferometric signal with a carrier signal at a reference frequency yields a low-frequency component (baseband signal) that contains the original signal's frequency. This method is commonly used for demodulation and extracting useful information from signals, particularly in wireless communication and signal processing.

[0055] It's important to note that low-pass filtering is a filtering technique used to remove frequencies above a specific range from a signal, retaining only the frequencies below that range. A low-pass filter allows signals with frequencies below the cutoff frequency to pass through, while attenuating or completely filtering out frequencies above that range. In interferometric signal processing, low-pass filtering is commonly used to remove high-frequency noise generated after mixing, retaining only the low-frequency components of the target signal, thereby improving signal quality and resolvability.

[0056] Optionally, the orthogonal interference signal pairs are specifically:

[0057]

[0058] Where 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.

[0059] In this invention, the main purpose of the mixing process is to convert high-frequency signals into lower-frequency signals that are easier to process. By mixing the interferometric signal with a carrier signal at a reference frequency, the high-frequency signal can be converted into a low-frequency baseband signal, making it easier to extract and analyze useful information from the signal. In interferometric signal processing, the mixed signal often contains some unwanted high-frequency noise components, which may affect the signal quality and accuracy. Low-pass filtering can effectively remove this high-frequency noise, retaining only the low-frequency portion of the target signal, thereby improving the signal quality and resolvability.

[0060] Optionally, the filter gain coefficient E1 of the sinusoidal component of the orthogonal interference signal pair, the filter gain coefficient E2 of the cosine component of the orthogonal interference signal pair, and the amplitude A1 of the AC component related to the optical power intensity of the reference light and the measurement light are eliminated from their influence on the demodulation process by signal normalization. Specifically, by normalizing the orthogonal interference signal pair, the amplitude of the signal is made independent of the above parameters in the calculation, thereby ensuring the accuracy and stability of the signal demodulation result without having to precisely solve for the actual values ​​of E1, E2, and A1.

[0061] Optionally, the phase modulation depth C is processed by combining Fast Fourier Transform (FFT) and Proportional-Integral-Derivative (PID) control. First, the spectrum of the interference signal is analyzed using the FFT algorithm to preliminarily estimate the value of the phase modulation depth C. Then, based on this, a closed-loop feedback system is constructed by introducing a PID controller to dynamically adjust and optimize the estimated value of C, ultimately adjusting it to the target value, thereby effectively eliminating nonlinear errors and harmonic distortion caused by inaccurate phase modulation depth.

[0062] It's important to note that the Fast Fourier Transform (FFT) is a highly efficient algorithm used to compute the Fourier transform of a signal. The Fourier transform converts a signal from the time domain to the frequency domain, revealing the amplitude and phase of each frequency component. The FFT algorithm makes this transformation process faster and more efficient by reducing computational complexity, making it particularly suitable for spectral analysis of large-scale data. In signal processing, the FFT can help analyze the frequency distribution in interferometric 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 proportional (P), integral (I), and derivative (D) components to control the system's output and achieve the desired target value. The proportional component applies control based on the magnitude of the error, the integral component accumulates the error to eliminate long-term deviations, and the derivative component anticipates and adjusts the system by predicting error trends. Through the combination of these three mechanisms, the PID controller can achieve precise system regulation and dynamic response.

[0064] In this invention, by normalizing the orthogonal interference signal pairs, the signal amplitude becomes independent of the filter gain coefficient and the AC component amplitude, thereby reducing the impact of these parameter variations on signal demodulation and ensuring the accuracy and stability of the demodulation results. Through the combination of PID control and FFT, the system can adapt to different signal variations and disturbances, maintaining good dynamic response and accuracy. The PID controller can adjust the phase modulation depth in real time, eliminating the influence of unstable factors or environmental disturbances, enabling the system to remain stable in complex environments.

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

[0066] It's important to note that a Lissajous curve is a curve plotted on a plane using two orthogonal (perpendicular) signals. It's commonly used to illustrate the relative frequency and phase relationships between signals. Specifically, the trajectory formed by the interaction of two signals as they vary along the x-axis and y-axis is the Lissajous curve. This curve is typically 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 will exhibit a regular geometric shape, such as an ellipse, circle, or bilobed shape. Lissajous curves can intuitively reflect the synchronicity and phase difference of signals and are frequently used in signal analysis and interferometry to help determine signal quality and existing errors.

[0067] In one possible implementation, S5 specifically includes:

[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 this invention, Lissajous figures are constructed to analyze orthogonal interferometric signal pairs. This method visually displays the relationship between the phase difference and frequency ratio between signals, effectively detecting the synchronicity, stability, and quality of the signals. Lissajous figures can reveal nonlinear errors and phase deviations in the signals, helping to identify and eliminate these errors and ensuring 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, improving the robustness of the system and simplifying the analysis process of complex signals, thus enhancing the efficiency of signal processing. Therefore, Lissajous figures provide an intuitive and efficient tool in interferometry for improving the accuracy, reliability, and adaptability of signals.

[0070] S6: Based on the Lissajous figure, determine if a carrier phase delay exists. If yes, proceed to the next step. Otherwise, no carrier phase delay compensation is needed.

[0071] Specifically, based on the Lissajous figure, the presence of carrier phase delay can be determined by analyzing its shape. When the carrier phase delay is zero, the Lissajous figure of an orthogonal interference signal pair is a standard circle. However, when a carrier phase delay exists, the Lissajous figure becomes elliptical, appearing as stretching or compression along a certain direction. Furthermore, the presence of carrier phase delay can be confirmed by calculating whether the normalized maximum values ​​of the Lissajous figure in both the horizontal and vertical axes are simultaneously equal to 1. If the normalized maximum value does not meet this condition, it indicates the presence of carrier phase delay, requiring compensation. If the normalized maximum value is simultaneously 1, no compensation is needed.

[0072] In this invention, the presence of carrier phase delay is determined by analyzing the shape of the Lissajous figure, enabling rapid and intuitive detection of phase errors. By observing the changes in the Lissajous figure, the figure is circular when the carrier phase delay is zero, and becomes elliptical when a phase delay exists. Furthermore, checking for the normalized maximum value effectively confirms whether compensation is needed, thereby avoiding unnecessary calculations and operations and improving efficiency. This method can accurately identify and compensate for phase delay, ensuring the accuracy and stability of signal demodulation, while saving computational resources and improving the system's automation and real-time feedback capabilities. In addition, through monitoring the Lissajous figure, the system can flexibly adjust and optimize phase compensation, enhancing the system's robustness in complex environments.

[0073] Reference manual attached Figure 2 The diagram illustrates the working principle of a single-chip microcomputer-based control system provided by an embodiment of the present invention.

[0074] S7: The microcontroller outputs a first control signal to control 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 output by the signal generator at the modulation end and demodulation end are the same, so as to compensate for the carrier phase delay.

[0075] Specifically, the microcontroller outputs a first control signal to control the signal generator, which then compensates for the phase θ. com Starting from 0, the frequency sweep is performed in steps with a phase increment of 0.1, continuously increasing the wave phase delay Δθ until Δθ + θ com =0. At this time, the first high-frequency carrier signal and the second high-frequency carrier signal output by the signal generator at the modulation end and 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 value of the Lissajous figure of the orthogonal interference signal pair in both the horizontal and vertical directions must be obtained and simultaneously reach the maximum value of 1, that is, the optimization goal is achieved (the normalized maximum value of the Lissajous figure of the orthogonal interference signal pair in both the horizontal and vertical directions simultaneously reaches 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 connected to the laser phase modulator at the modulation end and the signal acquisition card at the demodulation end, respectively.

[0078] In this invention, a microcontroller-controlled signal generator performs step-by-step frequency sweep adjustment to precisely compensate for carrier phase delay, ensuring that the high-frequency carrier signals at the modulation and demodulation ends are identical, thereby eliminating phase difference and optimizing signal demodulation. This process automatically detects and compensates for phase delay, guaranteeing the accuracy and stability of signal demodulation. When the carrier phase delay is eliminated, the Lissajous figure of the orthogonal interference signal pair reaches a normalized maximum value of 1 in both the horizontal and vertical axes, indicating that the system has reached its optimal state. Through automated control, this method simplifies the signal compensation process, improves the system's adaptability, stability, and measurement accuracy, while reducing manual intervention and increasing operational 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. md θ represents the amplitude of the first high-frequency carrier signal. com This indicates the compensation phase for frequency sweeping.

[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 This indicates the amplitude of the second high-frequency carrier signal.

[0085] In this invention, by designing the first and second high-frequency carrier signals separately and controlling their amplitudes and compensation phases, the modulation and demodulation processes can be precisely adjusted to ensure signal synchronization and accuracy. Independent control of the compensation phase and amplitude allows the system to flexibly adapt to different operating conditions, effectively eliminating errors caused by phase delay, thereby improving the accuracy of signal demodulation.

[0086] In one possible implementation, the process after S7 includes:

[0087] S8: When the first high-frequency carrier signal is the same as the second high-frequency carrier signal, the microcontroller outputs the second control signal to lock the phase of the high-frequency carrier signal output by the current signal generator at the demodulation end, controls the signal generator to stop performing 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 (i.e. when the optimization target is achieved), the microcontroller outputs a second control signal to lock the phase of the high-frequency carrier signal output by the current signal generator at the demodulation end, controls the signal generator to stop performing step frequency sweep, and sends a compensation completion signal to the computer, which records the current compensation phase and demodulation result.

[0089] In this invention, by stopping the step-by-step frequency sweep and locking the carrier signal phase at the demodulation end after carrier signal phase compensation is completed, the system can ensure the synchronization of carrier signals at the modulation and demodulation ends, thereby eliminating phase delay and improving demodulation accuracy and signal stability. Stopping the frequency sweep avoids unnecessary calculations and adjustments, improving system efficiency. Furthermore, the computer records the compensated phase and demodulation results in real time, enabling automated control and data feedback. This method not only reduces energy consumption but also ensures the stability and accuracy of the system in high-precision measurements, thus optimizing the entire signal processing process and improving the system's automation level and operational efficiency.

[0090] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0091] In this invention, the interference signal is decomposed using Bessel identities and trigonometric formulas to obtain the target interference signal. The DC component in the target interference signal is filtered out using AC coupling sampling. The DC-filtered target interference signal is then subjected to mixing and low-pass filtering to obtain an orthogonal interference signal pair. In practical applications, this is less susceptible to the effects of phase modulation depth and carrier phase delay, avoiding nonlinear errors and harmonic distortion. A first control signal is output from the microcontroller to control the signal generator to adjust the compensation phase and perform step-by-step frequency sweeping, preventing the carrier phase delay from drifting due to changes in unstable environmental factors. This maintains the accuracy of signal demodulation, thereby improving the accuracy of micro-vibration measurement.

[0092] Reference manual attached Figure 3 The diagram shows a schematic of a carrier phase delay compensation system based on microcontroller control provided by the present invention.

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

[0094] The memory 303 stores one or more application programs, which are adapted to be executed by the one or more processors 301 to implement the microcontroller-based carrier phase delay compensation method described in the method embodiment.

[0095] The microcontroller-based carrier phase delay compensation system 30 includes a processor 301 and a memory 303. The processor 301 and the memory 303 are connected, for example, via a bus 302.

[0096] The structure of the microcontroller-based carrier phase delay compensation system 30 does not constitute a limitation on the embodiments 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, transistor logic device, hardware component, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in connection with this disclosure. Processor 301 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0098] Bus 302 may include a pathway for transmitting information between the aforementioned components. Bus 302 may be a PCI bus or an EISA bus, etc. Bus 302 may be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the figure, but this does not mean that there is only one bus or one type of bus.

[0099] The memory 303 may be a ROM or other type of static storage device capable of storing static information and instructions, RAM or other type of dynamic storage device capable of storing information and instructions, or it may be an EEPROM, CD-ROM or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto.

[0100] It should be noted that the microcontroller-based carrier phase delay compensation system 30 can achieve the above-mentioned microcontroller-based carrier phase delay compensation method and can achieve the same or similar technical effects. To avoid repetition, the present invention will not elaborate further.

[0101] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0102] In this invention, the interference signal is decomposed using Bessel identities and trigonometric formulas to obtain the target interference signal. The DC component in the target interference signal is filtered out using AC coupling sampling. The DC-filtered target interference signal is then subjected to mixing and low-pass filtering to obtain an orthogonal interference signal pair. In practical applications, this is less susceptible to the effects of phase modulation depth and carrier phase delay, avoiding nonlinear errors and harmonic distortion. A first control signal is output from the microcontroller to control the signal generator to adjust the compensation phase and perform step-by-step frequency sweeping, preventing the carrier phase delay from drifting due to changes in unstable environmental factors. 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, the computer program being loadable and executed by a processor for the carrier phase delay compensation method based on microcontroller control as described in the first aspect.

[0104] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0105] The following points need to be explained:

[0106] (1) The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention. Other structures can refer to the general design.

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

[0108] (3) Where there is no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0109] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for carrier phase delay compensation based on single-chip microcomputer control, characterized in that, The method comprises the following steps: S1: determining an interference signal of a to-be-measured object based on the basic principle of a Michelson interferometer; S2: decomposing the interference signal to obtain a target interference signal by using the Bessel identity and a trigonometric function formula; S3: filtering out a direct current component in the target interference signal by using an alternating current coupling sampling mode; S4: performing a mixing processing and a low-pass filtering processing on the target interference signal after the direct current component is filtered out to obtain a pair of quadrature interference signals; S5: constructing a Lissajous figure according to the pair of quadrature interference signals; S6: determining whether a carrier phase delay exists according to the Lissajous figure; if yes, proceeding to the next step; otherwise, no carrier phase delay compensation is needed; S7: outputting a first control signal by using a single-chip microcomputer, and adjusting a compensation phase and performing a step-by-step frequency sweeping by using a signal generator until a first high-frequency carrier signal and a second high-frequency carrier signal output by the signal generator at a modulation end and a demodulation end are the same, so as to compensate the carrier phase delay; wherein the first high-frequency carrier signal is specifically as follows: wherein the second high-frequency carrier signal is specifically as follows: The S1 is specifically as follows: wherein, denotes the actual modulated carrier signal at the time instant t, i.e. the first high frequency carrier signal, t denotes the amplitude of the first high frequency carrier signal, denotes the cosine function, denotes the phase modulation depth carrier frequency, denotes the carrier phase delay, denotes the compensation phase for performing the sweep, denotes the compensation phase for performing the sweep. determining the interference signal of the to-be-measured object according to the following formula: wherein, denotes a carrier signal used for demodulation at the time instant t denotes a second high frequency carrier signal, denotes an amplitude of the second high frequency carrier signal.

2. The method of claim 1, wherein the single-chip microcomputer-based carrier phase delay compensation method is characterized by, The to-be-measured phase is specifically as follows: The S2 is specifically as follows: wherein, denotes the interference signal of the object under test at the time instant t t denotes the time instant, denotes the amplitude of the direct current component related to the light intensity, denotes the amplitude of the alternating current component related to the light power intensity of the reference light and the measurement light, denotes the cosine function, denotes the phase modulation depth, denotes the phase modulation depth carrier frequency, denotes the phase of the object under test at the time instant t t.​ 3. The method of claim 2, wherein the single-chip microcomputer-based carrier phase delay compensation method is characterized by, decomposing the interference signal to obtain the target interference signal by using the Bessel identity and the trigonometric function formula according to the following formula: wherein, k denotes the wave number, denotes the amplitude of the interference signal perturbation, denotes the sinusoidal function, denotes the angular frequency of the interference signal perturbation, denotes the initial phase of the interference signal perturbation, denotes the phase difference resulting from the initial optical path difference of the reference arm and the measurement arm.

4. The method of claim 1, wherein the single-chip microcomputer-based carrier phase delay compensation method is characterized by, The pair of quadrature interference signals is specifically as follows: The S5 is specifically as follows: wherein, denotes the target interference signal at the time instant t denotes the amplitude of the direct current component related to the light intensity, denotes the amplitude of the alternating current component related to the light power intensity of the reference light and the measurement light, denotes the cosine function, denotes the phase to be measured at the time instant t denotes the zeroth Bessel function, denotes the phase modulation depth, denotes the order of the Bessel function, denotes the Bessel function of order denotes the phase modulation depth carrier frequency, denotes the sine function, denotes the Bessel function of order​​ 5. The method of claim 1, wherein the single-chip microcomputer-based carrier phase delay compensation method is characterized by, constructing a Lissajous figure by taking a sine component of the pair of quadrature interference signals as an abscissa axis and taking a cosine component of the pair of quadrature interference signals as an ordinate axis. wherein denotes the sine component of the pair of quadrature interference signals at the time instant t denotes the filter gain coefficient of the sine component of the pair of quadrature interference signals, denotes the amplitude of the alternating component related to the optical power intensity of the reference light and the measurement light, denotes the first order Bessel function, denotes the phase modulation depth, denotes the cosine function, denotes the carrier phase delay, denotes the sine function, denotes the phase to be measured at the time instant t denotes the cosine component of the pair of quadrature interference signals at the time instant t denotes the filter gain coefficient of the cosine component of the pair of quadrature interference signals, denotes the second order Bessel function.​​​ 6. The method of claim 5, wherein the single-chip microcomputer-based carrier phase delay compensation method is characterized by, The method further comprises the following step after the S7: S8: when the first high-frequency carrier signal is the same as the second high-frequency carrier signal, outputting a second control signal by using the single-chip microcomputer, locking a high-frequency carrier signal phase output by the signal generator at the demodulation end, controlling the signal generator to stop the step-by-step frequency sweeping, and sending a compensation completion signal to a computer.

7. The method of claim 1, wherein the single-chip microcomputer-based carrier phase delay compensation method is characterized by, The device comprises: a memory and one or more processors; 8. A carrier phase delay compensation system based on microcontroller control, characterized in that, one or more application programs are stored in the memory, and the one or more application programs are adapted to be executed by the one or more processors to implement the single-chip microcomputer control-based carrier phase delay compensation method in any one of claims 1 to 7. ​ ​

Images