阅读说明：本技术 一种基于时域的相位分析方法、装置及系统 (Phase analysis method, device and system based on time domain ) 是由 姚远 刘海庆 揭银先 于 2020-12-22 设计创作，主要内容包括：本发明公开了一种基于时域的相位分析方法、装置及系统,包括：对两路数字信号的相邻采样点进行实时斜率计算,得到实时采样斜率值；当其中任一路数字信号的实时采样斜率值达到设定斜率值时,输出第一触发脉冲信号,根据第一触发脉冲信号触发所述该路数字信号,获取相位计算开始位；当另一路数字信号的实时采样斜率值达到所述设定斜率值时,输出第二触发脉冲信号,根据第二触发脉冲信号触发所述该路数字信号,获取相位计算结束位；计算上述相位计算开始位与相位计算结束位之间的时间差值,根据时间差值和模拟信号已知的周期信息,得到两路数字信号在时域下的相位差,实现外差干涉仪在时域上的相位分析。(The invention discloses a phase analysis method, a device and a system based on a time domain, comprising the following steps: carrying out real-time slope calculation on adjacent sampling points of the two paths of digital signals to obtain a real-time sampling slope value; when the real-time sampling slope value of any one path of digital signals reaches a set slope value, outputting a first trigger pulse signal, triggering the path of digital signals according to the first trigger pulse signal, and acquiring a phase calculation start bit; when the real-time sampling slope value of the other path of digital signal reaches the set slope value, outputting a second trigger pulse signal, triggering the path of digital signal according to the second trigger pulse signal, and acquiring a phase calculation end bit; and calculating the time difference between the phase calculation start bit and the phase calculation end bit, and obtaining the phase difference of the two paths of digital signals in the time domain according to the time difference and the known period information of the analog signal, so as to realize the phase analysis of the heterodyne interferometer in the time domain.)

1. A time domain-based phase analysis method, comprising:

respectively sampling two paths of analog signals with known periodic information to obtain digital signals, and performing real-time slope calculation on adjacent sampling points to obtain real-time sampling slope values;

when the real-time sampling slope value of any one path of digital signals reaches a set slope value, outputting a first trigger pulse signal, triggering the path of digital signals according to the first trigger pulse signal, and acquiring a phase calculation start bit;

when the real-time sampling slope value of the other path of digital signal reaches the set slope value, outputting a second trigger pulse signal, triggering the path of digital signal according to the second trigger pulse signal, and acquiring a phase calculation end bit;

and calculating the time difference between the phase calculation start bit and the phase calculation end bit, and obtaining the phase difference of the two paths of digital signals in the time domain according to the time difference and the known period information of the analog signal, so as to realize the phase analysis of the heterodyne interferometer in the time domain.

2. The phase analysis method based on the time domain according to claim 1, wherein the step of respectively sampling the two paths of analog signals with known period information to obtain digital signals and performing real-time slope calculation on adjacent sampling points to obtain real-time sampling slope values comprises:

converting an analog detection signal and an analog reference signal output by a detector into two paths of digital signals based on an analog-to-digital converter, wherein the two paths of digital signals are sine wave signals;

respectively determining sampling points of a set phase in one period of a sine wave in two paths of digital signals as set slope value sampling points, and taking a slope value calculated at the set slope value sampling points as a set slope value; and respectively carrying out real-time slope calculation on all sampling points on the two paths of digital signals to obtain a real-time sampling slope value, and storing the real-time sampling slope value.

3. The time-domain based phase analysis method of claim 2, wherein the phase calculation start bit or the phase calculation end bit is obtained as follows:

calculating the set slope threshold K of the sampling point of the set slope value in turn_x(X. 1, 2. cndot. N), said K_xSetting according to the signal-to-noise ratio of the signal;

judging whether the real-time sampling slope value is gradually changed to a set slope threshold value K or not_xWhen the change is over, a trigger signal is output;

and triggering the corresponding digital signal through the trigger signal to acquire a phase calculation starting bit or a phase calculation ending bit.

4. The phase analysis method based on the time domain according to claim 1, wherein the step of calculating the time difference between the phase calculation start bit and the phase calculation end bit, obtaining the phase difference of the two digital signals in the time domain according to the time difference and the known period information of the analog signal, and implementing the phase analysis of the heterodyne interferometer in the time domain comprises:

triggering a counter to start working by taking the trigger signal of any path as an enabling signal, stopping the counter from working when the trigger signal of the other path arrives, taking the output value of the counter as the time delay delta t between two paths of digital signals, and enabling the frequency of the counter to be equal to the sampling frequency;

the time delay amount Deltat, the trigger sequence of the trigger signal, and the period T of the sine wave signal are transmitted to the phase calculationIn the device, the phase difference of two paths of digital signals in the time domain is obtained

For phase differenceAnd real output is carried out, and phase analysis of the heterodyne interferometer on a time domain is realized.

5. The time-domain based phase analysis method of claim 4, wherein the phase differenceThe calculation is carried out according to the following formula:

6. a phase analysis device based on a time domain is characterized by comprising an analog-to-digital converter, a slope calculator, an edge detector, an exclusive-OR gate device, a register, a counter and a phase calculator, wherein the output end of the slope calculator is connected with the output end of the analog-to-digital converter, the output end of the slope calculator is respectively connected with the input end of the exclusive-OR gate device and the input end of the register, the output end of the exclusive-OR gate device is connected with the input end of the edge detector, the output end of the edge detector is connected with the input end of the counter, and the output end of the counter and the output end of the register are respectively connected with the input.

The analog-to-digital converter is used for respectively sampling two paths of analog signals with known period information to obtain digital signals;

the slope calculator is used for carrying out real-time slope calculation on adjacent sampling points in the digital signal to obtain a real-time sampling slope value;

the exclusive-OR gate device is used for outputting a first trigger pulse signal when the real-time sampling slope value of any one path of digital signals reaches a set slope value, triggering the path of digital signals according to the first trigger pulse signal to obtain a phase calculation starting bit, and outputting a second trigger pulse signal when the real-time sampling slope value of the other path of digital signals reaches the set slope value, triggering the path of digital signals according to the second trigger pulse signal to obtain a phase calculation ending bit;

the register is used for recording the trigger sequence of the trigger signal and sending the trigger sequence to the phase calculator;

the edge detector is used for detecting rising edges of the first trigger pulse signal and the second trigger pulse signal, outputting a high level between the two rising edges, and outputting a low level at the rest time;

the counter is used for calculating the time difference between the phase calculation starting bit and the phase calculation ending bit and sending the time difference to the phase calculator;

the phase calculator is used for obtaining the phase difference of the two paths of digital signals in the time domain according to the time difference, the triggering sequence and the known period information of the analog signals, and phase analysis of the heterodyne interferometer in the time domain is achieved.

7. A phase analysis system based on time domain is characterized by comprising a signal conversion module, a slope calculation module, a phase start bit calculation module, a phase end bit calculation module and a phase calculation module;

the signal conversion module is used for respectively sampling two paths of analog signals with known periodic information to obtain digital signals;

the slope calculation module is used for performing real-time slope calculation on adjacent sampling points to obtain a real-time sampling slope value;

the phase starting bit calculation module is used for outputting a first trigger pulse signal when the real-time sampling slope value of any one path of digital signals reaches a set slope value, triggering the path of digital signals according to the first trigger pulse signal and acquiring a phase calculation starting bit;

the phase end bit calculation module is used for outputting a second trigger pulse signal when the real-time sampling slope value of the other path of digital signal reaches the set slope value, triggering the path of digital signal according to the second trigger pulse signal and acquiring a phase calculation end bit;

the phase calculation module is used for calculating a time difference between the phase calculation start bit and the phase calculation end bit, obtaining a phase difference of the two paths of digital signals in a time domain according to the time difference and known period information of the analog signal, and realizing phase analysis of the heterodyne interferometer in the time domain.

8. A computer readable storage medium having stored thereon a number of acquisition classification procedures for being invoked by a processor and performing the phase analysis method of claim 1.

Technical Field

The present invention relates to the field of phase analysis technologies, and in particular, to a phase analysis method, device, and system based on a time domain.

Background

The interferometer is a high-precision instrument for measuring distance change, and is widely applied to plasma diagnosis and space distance detection. Heterodyne interferometers are one type of interferometer that can achieve better signal-to-noise ratio and accuracy through phase difference measurements than intensity-based measurements.

Currently, the well-established phase comparison methods commonly used on heterodyne interferometers include analog-based zero-crossing comparison and digital-based fourier transform analysis. The zero-crossing comparison method compares the phase difference between a detection track and a reference track in a period by judging the change of the amplitude value of an intermediate frequency sine wave signal from a negative value to a positive value, so that the method is influenced by the modulation intermediate frequency, and the phase resolution is an intermediate frequency value. Fourier transform analysis methods based on digital circuits require a complicated algorithm design, and digital signal processing including sine calculation, fourier transform, and the like is performed in a computer or a chip having a digital arithmetic function.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a phase analysis method, a phase analysis device and a phase analysis system based on a time domain, wherein the phase analysis based on the time domain is realized by comparing the sampling slope value and the set slope value of two paths of digital signals (sine wave signals).

The invention provides a phase analysis method based on a time domain, which comprises the following steps:

respectively sampling two paths of analog signals with known periodic information to obtain digital signals, and performing real-time slope calculation on adjacent sampling points to obtain real-time sampling slope values;

when the real-time sampling slope value of any one path of digital signals reaches a set slope value, outputting a first trigger pulse signal, triggering the path of digital signals according to the first trigger pulse signal, and acquiring a phase calculation start bit;

when the real-time sampling slope value of the other path of digital signal reaches the set slope value, outputting a second trigger pulse signal, triggering the path of digital signal according to the second trigger pulse signal, and acquiring a phase calculation end bit;

and calculating the time difference between the phase calculation start bit and the phase calculation end bit, and obtaining the phase difference of the two paths of digital signals in the time domain according to the time difference and the known period information of the analog signal, so as to realize the phase analysis of the heterodyne interferometer in the time domain.

Further, the steps of respectively sampling the two paths of analog signals with known periodic information to obtain digital signals, and performing real-time slope calculation on adjacent sampling points to obtain real-time sampling slope values include:

converting an analog detection signal and an analog reference signal output by a detector into two paths of digital signals based on an analog-to-digital converter, wherein the two paths of digital signals are sine wave signals;

respectively determining sampling points of a set phase in one period of a sine wave in two paths of digital signals as set slope value sampling points, and taking a slope value calculated at the set slope value sampling points as a set slope value; and respectively carrying out real-time slope calculation on all sampling points on the two paths of digital signals to obtain a real-time sampling slope value, and storing the real-time sampling slope value.

Further, the phase calculation start bit or the phase calculation end bit is obtained as follows:

calculating the set slope threshold K of the sampling point of the set slope value in turn_x(X. 1, 2. cndot. N), said K_xSetting according to the signal-to-noise ratio of the signal;

judging whether the real-time sampling slope value is gradually changed to a set slope threshold value K or not_xWhen the change is over, a trigger signal is output;

and triggering the corresponding digital signal through the trigger signal to acquire a phase calculation starting bit or a phase calculation ending bit.

Further, calculating a time difference between the phase calculation start bit and the phase calculation end bit, and obtaining a phase difference of the two paths of digital signals in the time domain according to the time difference and known period information of the analog signal, so as to implement phase analysis of the heterodyne interferometer in the time domain, the method includes:

triggering a counter to start working by taking the trigger signal of any path as an enabling signal, stopping the counter from working when the trigger signal of the other path arrives, taking the output value of the counter as the time delay delta t between two paths of digital signals, and enabling the frequency of the counter to be equal to the sampling frequency;

the time delay delta T, the triggering sequence of the triggering signals and the period T of the sine wave signals are transmitted to a phase calculator to obtain the phase difference of the two paths of digital signals in the time domain

For phase differenceAnd real output is carried out, and phase analysis of the heterodyne interferometer on a time domain is realized.

Further, the phase differenceThe calculation is carried out according to the following formula:

a phase analysis device based on a time domain comprises an analog-to-digital converter, a slope calculator, an exclusive-OR gate device, an edge detector, a register, a counter and a phase calculator, wherein the output end of the slope calculator is connected with the output end of the analog-to-digital converter, the output end of the slope calculator is respectively connected with the input end of the exclusive-OR gate device and the input end of the register, the output end of the exclusive-OR gate device is connected with the input end of the edge detector, the output end of the edge detector is connected with the input end of the counter, and the output end of the counter and the output end of the register are respectively connected with the.

The analog-to-digital converter is used for respectively sampling two paths of analog signals with known period information to obtain digital signals;

the slope calculator is used for carrying out real-time slope calculation on adjacent sampling points in the digital signal to obtain a real-time sampling slope value;

the exclusive-OR gate device is used for outputting a first trigger pulse signal when the real-time sampling slope value of any one path of digital signals reaches a set slope value, triggering the path of digital signals according to the first trigger pulse signal to obtain a phase calculation starting bit, and outputting a second trigger pulse signal when the real-time sampling slope value of the other path of digital signals reaches the set slope value, triggering the path of digital signals according to the second trigger pulse signal to obtain a phase calculation ending bit;

the edge detector is used for detecting rising edges of the first trigger pulse signal and the second trigger pulse signal, outputting a high level between the two rising edges, and outputting a low level at the rest time;

the register is used for recording the trigger sequence of the trigger signal and sending the trigger sequence to the phase calculator;

the counter is used for calculating the time difference between the phase calculation starting bit and the phase calculation ending bit and sending the time difference to the phase calculator;

the phase calculator is used for obtaining the phase difference of the two paths of digital signals in the time domain according to the time difference, the triggering sequence and the known period information of the analog signals, and phase analysis of the heterodyne interferometer in the time domain is achieved.

A phase analysis system based on time domain comprises a signal conversion module, a slope calculation module, a phase start bit calculation module, a phase end bit calculation module and a phase calculation module;

the signal conversion module is used for respectively sampling two paths of analog signals with known periodic information to obtain digital signals;

the slope calculation module is used for performing real-time slope calculation on adjacent sampling points to obtain a real-time sampling slope value;

the phase starting bit calculation module is used for outputting a first trigger pulse signal when the real-time sampling slope value of any one path of digital signals reaches a set slope value, triggering the path of digital signals according to the first trigger pulse signal and acquiring a phase calculation starting bit;

the phase end bit calculation module is used for outputting a second trigger pulse signal when the real-time sampling slope value of the other path of digital signal reaches the set slope value, triggering the path of digital signal according to the second trigger pulse signal and acquiring a phase calculation end bit;

the phase calculation module is used for calculating a time difference between the phase calculation start bit and the phase calculation end bit, obtaining a phase difference of the two paths of digital signals in a time domain according to the time difference and known period information of the analog signal, and realizing phase analysis of the heterodyne interferometer in the time domain.

The phase analysis method, the phase analysis device and the phase analysis system based on the time domain have the advantages that: according to the phase analysis method, the phase analysis device and the phase analysis system based on the time domain, provided by the structure, the sampling slope value and the set slope value of two paths of digital signals (sine wave signals) are compared, time delay information is obtained through direct measurement on the time domain to obtain a phase difference through conversion, and a high-precision delay unit based on a field programmable logic device FPGA is used for time measurement, so that the phase analysis based on the time domain is realized; a plurality of set slope values can be compared according to requirements, and the phase resolution of the heterodyne interferometer is improved; for signals with known different frequencies, the method can be directly applied to different heterodyne interferometers by correspondingly changing the period value; the requirement on the chip is low, the copying and the batch production are easy, a complex digital processing method is not needed, and the expense on a digital processing part in the chip is reduced.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic structural diagram of a phase analysis apparatus based on the time domain.

Detailed Description

The present invention is described in detail below with reference to specific embodiments, and in the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

As shown in fig. 1, a phase analysis method based on time domain proposed by the present invention includes:

s1: respectively sampling two paths of analog signals with known periodic information to obtain digital signals, and performing real-time slope calculation on adjacent sampling points to obtain real-time sampling slope values;

the analog signal can be converted into a digital signal through an analog-to-digital converter, the digital signal is a sine wave signal, and then a real-time sampling slope value is calculated on each sampling point on the digital signal through a slope calculator.

In the present application, the phase analysis preferably selects the phase measurement of the two paths of digital signals with the phase change of < 1% period.

S2: when the real-time sampling slope value of any one path of digital signals reaches a set slope value, outputting a first trigger pulse signal, triggering the path of digital signals according to the first trigger pulse signal, and acquiring a phase calculation start bit;

at the same time as the sampling start bit is acquired, the sampling start time point is also acquired.

S3: when the real-time sampling slope value of the other path of digital signal reaches the set slope value, outputting a second trigger pulse signal, triggering the path of digital signal according to the second trigger pulse signal, and acquiring a phase calculation end bit;

at the same time when the sampling end bit is acquired, the sampling end time point is also acquired. It should be noted that the set slope values for the two digital signals are the same value.

S4: and calculating the time difference between the phase calculation start bit and the phase calculation end bit, and obtaining the phase difference of the two paths of digital signals in the time domain according to the time difference and the known period information of the analog signal, so as to realize the phase analysis of the heterodyne interferometer in the time domain.

As can be seen from steps S1 to S4, the phase difference is obtained by comparing the sampling slope value of the two paths of digital signals (sine wave signals) with the set slope value and obtaining the time delay information through direct measurement in the time domain. The high-precision delay unit based on the field programmable logic device FPGA is used for time measurement, and phase analysis based on a time domain is realized.

It should be noted that, according to the present application, a plurality of set slope values are compared as required, so as to improve the phase resolution of the heterodyne interferometer; for signals with known different frequencies, the method can be directly applied to different heterodyne interferometers by correspondingly changing the period value, and the application range of the phase analysis method to different heterodyne interferometers is widened.

Further, at step S1: the method comprises the following steps of respectively sampling two paths of analog signals with known period information to obtain digital signals, and carrying out real-time slope calculation on adjacent sampling points to obtain real-time sampling slope values, wherein the steps comprise steps S11 to S13:

s11: converting an analog detection signal and an analog reference signal output by a detector into two paths of digital signals based on an analog-to-digital converter, wherein the two paths of digital signals are sine wave signals;

firstly, the analog detection signal and the analog reference signal respectively correspond to the two paths of analog signals with known period information recorded in the step S1, and before the analog detection signal and the analog reference signal are converted into two paths of digital signals; and modulating the analog detection signal and the analog reference signal to acquire information such as frequency, amplitude, shape and the like of the two paths of analog signals. The analog reference signal can be used as a reference signal to obtain a phase deviation value of the analog detection signal relative to the analog reference signal for phase analysis.

S12: respectively determining sampling points of a set phase in one period of a sine wave in two paths of digital signals as sampling points of a set slope value;

sampling points of phases of 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees and 315 degrees can be preset as sampling points of set slope values;

since it is obviously impractical to perform slope calculation for each point on the two digital signals, the two digital signals may be in the form of sine wave signals, and the 7 sampling points of 45 °, 90 °, 135 °, 180 °, 225 °, 270 °, and 315 ° are set in one period, respectively.

S13: and respectively carrying out real-time slope calculation on all sampling points on the two paths of digital signals to obtain a real-time sampling slope value, and storing the real-time sampling slope value.

Through steps S11 to S13, sampling slope values of the two paths of digital signals at the sampling points with set slope values can be obtained and stored as a comparison reference of the real-time sampling slope values to output a trigger signal, so that time delay information can be obtained through direct measurement in the time domain to obtain a phase difference through conversion.

Further, in acquiring the phase calculation start bit in step S3 and the phase calculation end bit in S4, it can be acquired by the following steps S21 to S23:

s21: calculating the set slope value K of the sampling point of the set slope value in turn_x(X. 1, 2. cndot. N), said K_xSetting according to the signal-to-noise ratio of the signal;

s22: obtaining and judging whether the real-time sampling slope value is gradually changed to a set slope value K_xWhen the change is over, a trigger signal is output;

s23: and triggering the corresponding digital signal through the trigger signal to acquire a phase calculation starting bit or a phase calculation ending bit.

As an embodiment, the steps S21 to S23 are specifically as follows:

s201: presetting set slope value sampling points as phase points of 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees and 315 degrees in a sine wave period;

s202: calculating the set slope value K of the sampling point of the set slope value in turn₁＝0.707,K₂＝0,K_3＝-0.707,K₄＝-1，K₅＝-0.707,K₆＝0,K₇＝0.707；K₁、K₂、K₃、K₃、K₄、K₅、K₆、K₇The slope values of 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees and 315 degrees correspond in sequence.

S203: will K₁As a set slope value, when the obtained real-time sampling slope value gradually changes to K₁Triggering a corresponding digital signal through a trigger signal to acquire a phase calculation starting bit or a phase calculation ending bit;

s204: then K is put₂As a new set slope value, step S203 is repeated, and so on, until K is reached₇Then, K is replaced₁As the next set slope value;

it should be noted that when the real-time sampling slope value is equal to K_xIf the difference value of (X ═ 1,2 · · 7) is larger, the current set slope value is kept unchanged, and whether the real-time sampling slope value reaches K or not is continuously judged_x. I.e. when the real-time sampling slope value changes by more than K₁But far from changing to K₂Stage, at this time, K₁As a set slope value until the real-time sampling slope value exceeds K₂Then, K is added₂As a set slope value.

In addition, K is_xWhen setting according to the signal-to-noise ratio of the signal, when the signal-to-noise ratio is good, for K₁For 0.707, K may be set₁Is in the judgment range of 0.705-0.709; accordingly, when the signal-to-noise ratio is poor, for K₁0.707 may be set to a determination range of 0.685 to 0.715; so as to adapt to the use of a certain amplitude error of the actual phase analysis equipment.

Therefore, through steps S201 to S204, the two digital signals pass through the set slope value (e.g. K) sampled from the same set slope value₁) Comparing to obtain corresponding trigger signals, wherein the trigger signals corresponding to the two digital signals have a certain time delay, that is, a certain time difference exists between the phase calculation start bit and the phase calculation end bit, and the phase difference between the two digital signals can be obtained according to the time difference, the known period information of the analog signal and the trigger sequence of the two digital signals, thereby realizing the phase difference of the heterodyne interferometer in the time domainAnd (6) analyzing.

Meanwhile, the phase analysis method is superior to the phase measurement suitable for two digital signal phase changes of < 1% period; but does not exclude phase measurements suitable for two digital signals with a phase change of more than 1% of a period.

Further, at step S4: calculating a time difference between the phase calculation start bit and the phase calculation end bit, and obtaining a phase difference of the two paths of digital signals in a time domain according to the time difference and known period information of the analog signal, so as to realize phase analysis of the heterodyne interferometer in the time domain, wherein the phase difference comprises the following steps:

s41: triggering a counter to start working by taking the trigger signal of any path as an enabling signal, stopping the counter from working when the trigger signal of the other path arrives, taking the output value of the counter as the time delay delta t between two paths of digital signals, and enabling the frequency of the counter to be equal to the sampling frequency;

the real-time slope value of the two paths of digital signals is equal to a set slope value K_xAnd when the counter reaches the 'reach' state, the counter is connected to the input end of the edge detector in an exclusive OR mode, and the edge detector outputs a high level to the enabling end of the counter between two rising edges so that the counter acquires a trigger signal of the 'reach' state.

Recording the arrival sequence of the 'reach' state by using a special register, if one path of digital signal is set to be 1 and the other path of digital signal is set to be 2, when the 'reach' state of the 1 path arrives first, setting the value of the register to be 10 of a second-level system; when the 2-way "reach" state comes first, then the value of the register is set to binary 01.

S42: the time delay delta T, the triggering sequence of the triggering signals and the period T of the sine wave signals are transmitted to a phase calculator to obtain the phase difference of the two paths of digital signals in the time domainThe formula is as follows:

s43: the phase difference is output in real time, and phase analysis of the heterodyne interferometer on a time domain is achieved.

Through steps S41 to S44, time measurements with a precision of more than 100 picoseconds can be made with the FPGA architecture, which can satisfy most of the current requirements for interferometers for tokamak devices. The time difference and the phase difference of the two paths of digital signals are calculated through the FPGA structure, and the phase analysis of the heterodyne interferometer based on the time domain is realized.

As shown in fig. 2, a phase analysis apparatus based on a time domain includes an analog-to-digital converter and an FPGA, where the FPGA includes a slope calculator, an xor gate device, a register, an edge detector, a counter, and a phase calculator, an output end of the slope calculator is connected to an output end of the analog-to-digital converter, an output end of the slope calculator is connected to an input end of the xor gate device and an input end of the register, respectively, an output end of the xor gate device is connected to an input end of the edge detector, an output end of the edge detector is connected to an input end of the counter, and an output end of the counter and an output end of the register are connected to an input.

The analog-to-digital converter is used for respectively sampling two paths of analog signals with known period information to obtain digital signals;

the slope calculator is used for carrying out real-time slope calculation on adjacent sampling points in the digital signal to obtain a real-time sampling slope value;

the exclusive-OR gate device is used for outputting a first trigger pulse signal when the real-time sampling slope value of any one path of digital signals reaches a set slope value, triggering the path of digital signals according to the first trigger pulse signal to obtain a phase calculation starting bit, and outputting a second trigger pulse signal when the real-time sampling slope value of the other path of digital signals reaches the set slope value, triggering the path of digital signals according to the second trigger pulse signal to obtain a phase calculation ending bit;

the register is used for recording the trigger sequence of the trigger signal and sending the trigger sequence to the phase calculator;

the edge detector is used for detecting rising edges of the first trigger pulse signal and the second trigger pulse signal, outputting a high level between the two rising edges, and outputting a low level at the rest time; i.e. the enable of the counter is triggered by the high level output by the edge detector, so that the counter is triggered blessing, at which time the counter gets the trigger signal "reach" state. The "reached" state is a phase calculation start bit or a phase calculation end bit.

The counter is used for calculating the time difference between the phase calculation starting bit and the phase calculation ending bit and sending the time difference to the phase calculator;

the phase calculator is used for obtaining the phase difference of the two paths of digital signals in the time domain according to the time difference, the triggering sequence and the known period information of the analog signals, and phase analysis of the heterodyne interferometer in the time domain is achieved.

A phase analysis system based on time domain comprises a signal conversion module, a slope calculation module, a phase start bit calculation module, a phase end bit calculation module and a phase calculation module;

the signal conversion module is used for respectively sampling two paths of analog signals with known periodic information to obtain digital signals;

the slope calculation module is used for performing real-time slope calculation on adjacent sampling points to obtain a real-time sampling slope value;

the phase starting bit calculation module is used for outputting a first trigger pulse signal when the real-time sampling slope value of any one path of digital signals reaches a set slope value, triggering the path of digital signals according to the first trigger pulse signal and acquiring a phase calculation starting bit;

the phase end bit calculation module is used for outputting a second trigger pulse signal when the real-time sampling slope value of the other path of digital signal reaches the set slope value, triggering the path of digital signal according to the second trigger pulse signal and acquiring a phase calculation end bit;

the phase calculation module is used for calculating a time difference value between the phase calculation start bit and the phase calculation end bit, obtaining a phase difference of the two paths of digital signals in a time domain according to the time difference value and known period information of the analog signal, and realizing phase analysis of the heterodyne interferometer in the time domain

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.