CN113607046A - Laser interferometry signal processing device and signal subdivision method - Google Patents

Laser interferometry signal processing device and signal subdivision method Download PDF

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CN113607046A
CN113607046A CN202110875062.7A CN202110875062A CN113607046A CN 113607046 A CN113607046 A CN 113607046A CN 202110875062 A CN202110875062 A CN 202110875062A CN 113607046 A CN113607046 A CN 113607046A
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CN113607046B (en
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刘小为
黄强先
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Hefei University of Technology
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    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
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    • G—PHYSICS
    • G01—MEASURING; TESTING
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Abstract

本发明涉及一种激光干涉测量信号处理装置，包括四倍程偏振光单元，所述四倍程偏振光单元的输出端与光电信号转换单元的输入端相连，光电信号转换单元的输出端与信号前置放大调理单元的输入端相连，信号前置放大调理单元的输出端与信号差分运算单元的输入端相连，信号差分运算单元的输出端与正交信号补偿单元的输入端相连，正交信号补偿单元的输出端与正交信号差值细分计数单元的输入端相连。本发明还公开了一种激光干涉测量信号处理装置的信号细分方法。本发明使测量系统的分辨率提高了800倍，从而满足了激光干涉测量系统的高精度要求，提高了激光干涉位移测量系统的动态能力，系统动态频率测量响应由0.1秒提升为0.04秒。

Figure 202110875062

The invention relates to a laser interferometric measurement signal processing device, comprising a quadruple-range polarized light unit, an output end of the quadruple-range polarized light unit is connected with an input end of a photoelectric signal conversion unit, and an output end of the photoelectric signal conversion unit is connected to a signal The input end of the preamplification conditioning unit is connected, the output end of the signal preamplification conditioning unit is connected with the input end of the signal differential operation unit, the output end of the signal difference operation unit is connected with the input end of the quadrature signal compensation unit, and the quadrature signal The output end of the compensation unit is connected with the input end of the quadrature signal difference subdivision counting unit. The invention also discloses a signal subdivision method of the laser interferometric signal processing device. The present invention increases the resolution of the measurement system by 800 times, thereby meeting the high-precision requirements of the laser interference measurement system, improving the dynamic capability of the laser interference displacement measurement system, and the dynamic frequency measurement response of the system is improved from 0.1 seconds to 0.04 seconds.

Figure 202110875062

Description

Laser interferometry signal processing device and signal subdivision method
Technical Field
The invention relates to the technical field of high-precision measurement, in particular to a laser interference measurement signal processing device and a signal subdivision method.
Background
To make interferometers achieve high precision measurements with nanometer-scale accuracy, high resolution is first obtained. At present, there are two main methods for improving the resolution of an interferometer: firstly, interference signals are subdivided through a circuit; the second is to multiply the optical path difference. The laser interference measuring system has limited frequency multiplication of optical path difference due to factors such as structure, and the measurement accuracy provided by the laser interference measuring system depends on a signal processing and subdivision method to a great extent.
The method comprises the following steps of subdividing two periodic orthogonal signals output by an interferometer, wherein if hardware subdivision is adopted, the higher the subdivision number is, the more complex an electronic system is, and the nonlinear error can be added to the system due to noise brought by a processing circuit; if software subdivision is adopted, subdivision is usually realized by using a method of distinguishing trigrams and table lookup, but a program and a tangent table need to be modified to realize high-power subdivision, the software query is slow in subdivision speed, and the method is mainly used for a measuring system with low input signal frequency, and restricts the application of a laser interference measuring system in real-time, high-speed and other scenes to a certain extent.
Disclosure of Invention
The invention aims to provide a laser interference measurement signal processing device which can improve the resolution of a laser interference displacement measurement system so as to meet the requirements of high precision, high speed and real-time dynamic response of the laser interference measurement system.
In order to achieve the purpose, the invention adopts the following technical scheme: a laser interferometry signal processing apparatus comprising:
the quadruple path polarized light unit adopts a polarized beam splitter and a lambda/4 wave plate, and performs 4-time subdivision on the signals by using an optical path difference amplification technology, and the interference fringes perform spatial phase shifting to obtain four paths of interference output light intensity signals E1, E2, E3 and E4 with phases different by 90 degrees in sequence;
the photoelectric signal conversion unit adopts a four-path photoelectric detector to convert four-path light intensity signals E1, E2, E3 and E4 into four-path orthogonal current signals I1, I2, I3 and I4 respectively;
the signal pre-amplification conditioning unit converts current signals I1, I2, I3 and I4 into voltage signals V1, V2, V3 and V4 by adopting I/F conversion setting, and performs post-stage operational amplification and conditioning on the voltage signals V1, V2, V3 and V4 by adopting an amplification circuit, a direct current regulation circuit and a low-pass filter circuit;
the signal difference operation unit eliminates direct current components in signals of two interference light signals with opposite phases of V1, V2, V3 and V4 through an addition circuit to obtain two orthogonal signals with better common mode rejection, sends the two paths of differential interference signals into an analog circuit for further amplification and conditioning, subtracts every two of four paths of voltage signals of V1, V2, V3 and V4 with opposite phases through a subtraction circuit, and outputs orthogonal voltage signals of V5 and V6;
the orthogonal signal compensation unit is used for carrying out high-speed real-time automatic correction and compensation according to an orthogonal vector circle correction model after carrying out A/D high-speed conversion on the orthogonal voltage signals V5 and V6, and synthesizing the voltage signals V5 and V6 into a vector circle signal V7;
the orthogonal signal interpolation subdivision counting unit is used for continuously interpolating vector circle signals V7 in each signal period, counting the signal periods by matching with a 20-bit reversible counter and carrying out 16-bit interpolation subdivision on the signals in two paths of orthogonal signal periods at 8M/S high-speed A/D sampling frequency;
the output end of the quadruple-path polarized light unit is connected with the input end of the photoelectric signal conversion unit, the output end of the photoelectric signal conversion unit is connected with the input end of the signal pre-amplification conditioning unit, the output end of the signal pre-amplification conditioning unit is connected with the input end of the signal differential operation unit, the output end of the signal differential operation unit is connected with the input end of the orthogonal signal compensation unit, and the output end of the orthogonal signal compensation unit is connected with the input end of the orthogonal signal differential value subdivision counting unit.
The orthogonal signal interpolation subdivision unit comprises:
the reversible calculation module adopts a bidirectional counter for forward/reverse parallel counting and 20-bit binary complement codes to count the whole period signals for forward and reverse displacement measurement;
the interpolation module is used for carrying out 16-bit continuous interpolation on the monocycle signals and outputting interpolation numbers in real time;
and the resetting module starts an alarm function and resets the module in time when the relative errors of the direct current level and the amplitude drift of the orthogonal signal are more than 5% and the vector circle signal V7 is abnormal.
Another object of the present invention is to provide a signal subdivision method of a laser interferometry signal processing apparatus, the method comprising the following sequential steps:
(1) initializing, carrying out 4-time signal subdivision on interference fringes through a polarization beam splitter of a quadruple-time polarization light unit and a lambda/4 wave plate, and obtaining four paths of interference output light intensity signals E1, E2, E3 and E4 with phases different by 90 degrees in sequence through spatial phase shifting;
(2) the four-channel detection circuit with differential zero-offset design is adopted to carry out photoelectric conversion through the photoelectric signal conversion unit, and four paths of interference output light intensity signals E1, E2, E3 and E4 of the quadruple-path polarized light unit are converted into current signals I1, I2, I3 and I4 respectively;
(3) then, the current signals I1, I2, I3 and I4 are converted into voltage signals V1, V2, V3 and V4 by a signal pre-amplification conditioning unit and a current conversion voltage circuit, and the voltage signals are subjected to operational amplification and conditioning by an amplifying circuit, a direct current regulating circuit and a low-pass filter circuit;
(4) then two interference light signals with opposite phases of V1, V2, V3 and V4 are eliminated by a signal difference operation unit through a summing circuit to obtain two orthogonal signals with better common mode rejection, the two differential interference signals are sent to an analog circuit for further amplification and conditioning, after passing through each stage of processing circuits in the unit device, four voltage signals with opposite phases are subtracted by a subtraction circuit in pairs, namely V1-V2 and V3-V4, and finally two orthogonal voltage signals V5 and V6 with 90-degree phase difference are obtained;
(5) then, the orthogonal signal compensation unit is used for carrying out A/D high-speed conversion on the two processed orthogonal voltage signals V5 and V6, loading an orthogonal vector circle correction model, carrying out high-speed real-time automatic correction and compensation, and synthesizing the voltage signals V5 and V6 into a vector signal V7;
(6) then, through an orthogonal signal interpolation subdivision counting unit, when the periodic signal is counted, the signal with less than one period is interpolated; and judging whether the orthogonal vector composite signal has interpolation, if not, automatically correcting and then carrying out interpolation subdivision.
The orthogonal vector circle correction model in the step (5) specifically includes:
when two paths of orthogonal signals have non-orthogonality and non-equal amplitude, the component of the vector composite signal V7 in the X, Y axis direction is expressed as:
Figure BDA0003190037820000031
wherein, I'xIs the component, I ', of the vector signal V7 in the X-axis direction'yAs a component of the vector signal V7 in the Y-axis direction, α represents a non-orthogonal error; g is the ratio of the amplitudes of the two paths of measurement signals; p and q are the direct current drift sizes of the two paths of measurement signals respectively; when α ≠ 0, G ≠ 1, or p ≠ q, the resultant vector circle signal is an ellipse instead of a standard circle, where the relationship of the ellipse equation to G, p, q is described as:
Figure BDA0003190037820000032
the formula (1-2) is simplified as follows:
Figure BDA0003190037820000041
wherein, R is the variable radius of the elliptic equation, A, B, C, D, E are respectively different coefficients of the elliptic equation, and the coefficient A is R2cos2α-p2-G2q2-2 Gpqsin α; coefficient B ═ G2(ii) a The coefficient C ═ 2Gsin α; the coefficient D is 2p +2Gqsin α; coefficient E ═ 2G2q+2Gpsinα；
The coefficients A, B, C, D, E are respectively calculated and solved by a multiple linear regression method to obtain alpha, G, R, p and q, which are expressed as the formula (1-4):
Figure BDA0003190037820000042
with compensation correction, the vector signal synthesis is a standard circular vector signal V7:
Figure BDA0003190037820000043
the step (6) of determining whether the orthogonal vector composite signal has interpolation, and if not, the step of automatically correcting and then subdividing the interpolation specifically includes:
(6a) firstly, starting judgment, judging whether the relative errors of phase angle orthogonality, direct current level and amplitude drift of an original signal are less than 5%, and automatically correcting and compensating to enable a synthetic vector circle signal V7 to be a standard circle;
(6b) recording the count N of the measured forward and reverse whole-period signals through a 20-bit binary complement reversible calculation circuit;
(6c) then 16-bit interpolation sampling is carried out on the non-full-period signal at the rate of 8M/S, the waveform, the amplitude and the phase of the synthetic vector circular signal V7 are respectively subjected to interpolation sampling, and the signal is subdivided by 200 times by adopting a mapping transformation mode and a subdivision algorithm;
(6d) finally, by synthesizing the signal 4 times subdivision of the quadruple path polarized light unit and the orthogonal signal interpolation counting 200 times subdivision, the 800 times signal subdivision of the laser wavelength lambda of the laser interference displacement measurement system is finally realized, so that the resolution of the laser interference displacement measurement system reaches lambda/800;
(6e) when the relative error of the phase orthogonality, the direct current level and the amplitude drift of the orthogonal signal is larger than 5%, the vector circle signal V7 is distorted, the subdivision counting of the interpolation signal is stopped, and the laser interferometry signal processing device is reset again.
According to the technical scheme, the beneficial effects of the invention are as follows: firstly, the invention eliminates the direct current component of the signal, can improve the quality of the interference signal and realize the measurement signal of the laser interferometer, adopts the high-speed interpolation subdivision technology, and has higher speed and higher dynamic response compared with the traditional subdivision technology. Secondly, the invention adopts a signal subdivision method, firstly subdivides signals by adopting a 4-time double-pass technology, and then realizes 200-time signal subdivision of 16-bit continuous interpolation at high speed through the signal processing device, so that the resolution of a final measurement system is improved by 800 times, and the dynamic response of the system is shortened to 0.01 second.
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FIG. 1 is a schematic block diagram of the apparatus of the present invention;
fig. 2 is a flow chart of the method of the present invention.
Detailed Description
As shown in fig. 1, a laser interferometry signal processing apparatus includes:
the quadruple path polarized light unit adopts a polarized beam splitter and a lambda/4 wave plate, and performs 4-time subdivision on the signals by using an optical path difference amplification technology, and the interference fringes perform spatial phase shifting to obtain four paths of interference output light intensity signals E1, E2, E3 and E4 with phases different by 90 degrees in sequence;
the photoelectric signal conversion unit adopts a four-path photoelectric detector to convert four-path light intensity signals E1, E2, E3 and E4 into four-path orthogonal current signals I1, I2, I3 and I4 respectively;
the signal pre-amplification conditioning unit converts current signals I1, I2, I3 and I4 into voltage signals V1, V2, V3 and V4 by adopting I/F conversion setting, and performs post-stage operational amplification and conditioning on the voltage signals V1, V2, V3 and V4 by adopting an amplification circuit, a direct current regulation circuit and a low-pass filter circuit;
the signal difference operation unit eliminates direct current components in signals of two interference light signals with opposite phases of V1, V2, V3 and V4 through an addition circuit to obtain two orthogonal signals with better common mode rejection, sends the two paths of differential interference signals into an analog circuit for further amplification and conditioning, subtracts every two of four paths of voltage signals of V1, V2, V3 and V4 with opposite phases through a subtraction circuit, and outputs orthogonal voltage signals of V5 and V6;
the orthogonal signal compensation unit is used for carrying out high-speed real-time automatic correction and compensation according to an orthogonal vector circle correction model after carrying out A/D high-speed conversion on the orthogonal voltage signals V5 and V6, and synthesizing the voltage signals V5 and V6 into a vector circle signal V7;
the orthogonal signal interpolation subdivision counting unit is used for continuously interpolating vector circle signals V7 in each signal period, counting the signal periods by matching with a 20-bit reversible counter and carrying out 16-bit interpolation subdivision on the signals in two paths of orthogonal signal periods at 8M/S high-speed A/D sampling frequency;
the output end of the quadruple-path polarized light unit is connected with the input end of the photoelectric signal conversion unit, the output end of the photoelectric signal conversion unit is connected with the input end of the signal pre-amplification conditioning unit, the output end of the signal pre-amplification conditioning unit is connected with the input end of the signal differential operation unit, the output end of the signal differential operation unit is connected with the input end of the orthogonal signal compensation unit, and the output end of the orthogonal signal compensation unit is connected with the input end of the orthogonal signal differential value subdivision counting unit.
The orthogonal signal interpolation subdivision unit comprises:
the reversible calculation module adopts a bidirectional counter for forward/reverse parallel counting and 20-bit binary complement codes to count the whole period signals for forward and reverse displacement measurement;
the interpolation module is used for carrying out 16-bit continuous interpolation on the monocycle signals and outputting interpolation numbers in real time;
and the resetting module starts an alarm function and resets the module in time when the relative errors of the direct current level and the amplitude drift of the orthogonal signal are more than 5% and the vector circle signal V7 is abnormal.
As shown in fig. 2, the method comprises the following sequence of steps:
(1) initializing, carrying out 4-time signal subdivision on interference fringes through a polarization beam splitter of a quadruple-time polarization light unit and a lambda/4 wave plate, and obtaining four paths of interference output light intensity signals E1, E2, E3 and E4 with phases different by 90 degrees in sequence through spatial phase shifting;
(2) the four-channel detection circuit with differential zero-offset design is adopted to carry out photoelectric conversion through the photoelectric signal conversion unit, and four paths of interference output light intensity signals E1, E2, E3 and E4 of the quadruple-path polarized light unit are converted into current signals I1, I2, I3 and I4 respectively;
(3) then, the current signals I1, I2, I3 and I4 are converted into voltage signals V1, V2, V3 and V4 by a signal pre-amplification conditioning unit and a current conversion voltage circuit, and the voltage signals are subjected to operational amplification and conditioning by an amplifying circuit, a direct current regulating circuit and a low-pass filter circuit;
(4) then two interference light signals with opposite phases of V1, V2, V3 and V4 are eliminated by a signal difference operation unit through a summing circuit to obtain two orthogonal signals with better common mode rejection, the two differential interference signals are sent to an analog circuit for further amplification and conditioning, after passing through each stage of processing circuits in the unit device, four voltage signals with opposite phases are subtracted by a subtraction circuit in pairs, namely V1-V2 and V3-V4, and finally two orthogonal voltage signals V5 and V6 with 90-degree phase difference are obtained;
(5) then, the orthogonal signal compensation unit is used for carrying out A/D high-speed conversion on the two processed orthogonal voltage signals V5 and V6, loading an orthogonal vector circle correction model, carrying out high-speed real-time automatic correction and compensation, and synthesizing the voltage signals V5 and V6 into a vector signal V7;
(6) then, through an orthogonal signal interpolation subdivision counting unit, when the periodic signal is counted, the signal with less than one period is interpolated; and judging whether the orthogonal vector composite signal has interpolation, if not, automatically correcting and then carrying out interpolation subdivision.
The orthogonal vector circle correction model in the step (5) specifically includes:
when two paths of orthogonal signals have non-orthogonality and non-equal amplitude, the component of the vector composite signal V7 in the X, Y axis direction is expressed as:
Figure BDA0003190037820000071
wherein, I'xIs the component, I ', of the vector signal V7 in the X-axis direction'yAs a component of the vector signal V7 in the Y-axis direction, α represents a non-orthogonal error; g is the ratio of the amplitudes of the two paths of measurement signals; p and q are the direct current drift sizes of the two paths of measurement signals respectively; when α ≠ 0, G ≠ 1, or p ≠ q, the resultant vector circle signal is an ellipse instead of a standard circle, where the relationship of the ellipse equation to G, p, q is described as:
Figure BDA0003190037820000072
the formula (1-2) is simplified as follows:
Figure BDA0003190037820000073
wherein, R is the variable radius of the elliptic equation, A, B, C, D, E are respectively different coefficients of the elliptic equation, and the coefficient A is R2cos2α-p2-G2q2-2 Gpqsin α; coefficient B ═ G2(ii) a The coefficient C ═ 2Gsin α; the coefficient D is 2p +2Gqsin α; coefficient E ═ 2G2q+2Gpsinα；
The coefficients A, B, C, D, E are respectively calculated and solved by a multiple linear regression method to obtain alpha, G, R, p and q, which are expressed as the formula (1-4):
Figure BDA0003190037820000081
with compensation correction, the vector signal synthesis is a standard circular vector signal V7:
Figure BDA0003190037820000082
the step (6) of determining whether the orthogonal vector composite signal has interpolation, and if not, the step of automatically correcting and then subdividing the interpolation specifically includes:
(6a) firstly, starting judgment, judging whether the relative errors of phase angle orthogonality, direct current level and amplitude drift of an original signal are less than 5%, and automatically correcting and compensating to enable a synthetic vector circle signal V7 to be a standard circle;
(6b) recording the count N of the measured forward and reverse whole-period signals through a 20-bit binary complement reversible calculation circuit;
(6c) then 16-bit interpolation sampling is carried out on the non-full-period signal at the rate of 8M/S, the waveform, the amplitude and the phase of the synthetic vector circular signal V7 are respectively subjected to interpolation sampling, and the signal is subdivided by 200 times by adopting a mapping transformation mode and a subdivision algorithm;
(6d) finally, by synthesizing the signal 4 times subdivision of the quadruple path polarized light unit and the orthogonal signal interpolation counting 200 times subdivision, the 800 times signal subdivision of the laser wavelength lambda of the laser interference displacement measurement system is finally realized, so that the resolution of the laser interference displacement measurement system reaches lambda/800;
(6e) when the relative error of the phase orthogonality, the direct current level and the amplitude drift of the orthogonal signal is larger than 5%, the vector circle signal V7 is distorted, the subdivision counting of the interpolation signal is stopped, and the laser interferometry signal processing device is reset again.
In conclusion, the invention can realize the improvement of the resolution of the laser interference measurement system, the resolution of the measurement system is improved by 800 times by adopting the 4-time subdivision of the optical octave and the high-speed 16-bit continuous interpolation 200 subdivision method of the device, thereby meeting the high-precision requirement of the laser interference measurement system, the dynamic capacity of the laser interference displacement measurement system is improved by adopting the high-speed signal processing and continuous interpolation technology, and the dynamic frequency measurement response of the system is improved from 0.1 second to 0.04 second.

Claims (5)

1.一种激光干涉测量信号处理装置，其特征在于：包括：1. A laser interferometry signal processing device is characterized in that: comprising: 四倍程偏振光单元，采用偏振分光镜以及λ/4波片，利用光程差放大技术对信号进行4倍细分，干涉条纹进行空间移相得到相位依次相差90°的四路干涉输出光强信号E1、E2、E3、E4；The quadruple path polarizing light unit uses a polarizing beam splitter and a λ/4 wave plate, uses the optical path difference amplification technology to subdivide the signal by 4 times, and performs spatial phase shifting of the interference fringes to obtain four channels of interference output light with a phase difference of 90°. Strong signal E1, E2, E3, E4; 光电信号转换单元，采用四路光电探测器使四路光强信号E1、E2、E3、E4分别转换为四路正交的电流信号I1、I2、I3、I4；The photoelectric signal conversion unit adopts four photoelectric detectors to convert the four light intensity signals E1, E2, E3 and E4 into four quadrature current signals I1, I2, I3 and I4 respectively; 信号前置放大调理单元，采用I/F转化设置将电流信号I1、I2、I3、I4转化为电压信号V1、V2、V3、V4，并对其进行后级采取放大电路、直流调节电路、低通滤波电路后运算放大与调理；The signal pre-amplification and conditioning unit uses the I/F conversion setting to convert the current signals I1, I2, I3, and I4 into voltage signals V1, V2, V3, and V4, and uses the amplifier circuit, DC adjustment circuit, low Operational amplification and conditioning after passing through the filter circuit; 信号差分运算单元，将V1、V2、V3、V4相位相反的两个干涉光信号通过加法电路消除信号中的直流分量，得到两个共模抑制比较好正交信号再将这两路差动干涉信号送入模拟电路进一步放大和调理，再采用减法电路对相位相反的四路V1、V2、V3、V4电压信号两两相减，输出正交电压信号V5和V6；Signal differential operation unit, which uses two interfering optical signals with opposite phases of V1, V2, V3, and V4 to eliminate the DC component in the signal through the addition circuit, and obtains two quadrature signals with better common mode suppression, and then the two channels are differentially interfered. The signal is sent to the analog circuit for further amplification and conditioning, and then the four-way V1, V2, V3, V4 voltage signals with opposite phases are subtracted by the subtraction circuit, and the quadrature voltage signals V5 and V6 are output; 正交信号补偿单元，对正交电压信号V5和V6进行A/D高速转换后，依据正交矢量圆修正模型，进行高速实时自动修正和补偿，并将电压信号V5和V6合成为矢量圆信号V7；The quadrature signal compensation unit performs A/D high-speed conversion on the quadrature voltage signals V5 and V6, performs high-speed real-time automatic correction and compensation according to the quadrature vector circle correction model, and synthesizes the voltage signals V5 and V6 into a vector circle signal V7; 正交信号插值细分计数单元，在每个信号周期内对矢量圆信号V7进行连续插值，配合20位可逆计数器对信号周期进行计数，对两路正交信号周期内对信号以8M/S高速A/D采样频率进行16位插值细分；The quadrature signal interpolation subdivision counting unit continuously interpolates the vector circle signal V7 in each signal period, and cooperates with a 20-bit reversible counter to count the signal period, and counts the signals at a high speed of 8M/S in the two-way quadrature signal period. A/D sampling frequency for 16-bit interpolation subdivision; 所述四倍程偏振光单元的输出端与光电信号转换单元的输入端相连，光电信号转换单元的输出端与信号前置放大调理单元的输入端相连，信号前置放大调理单元的输出端与信号差分运算单元的输入端相连，信号差分运算单元的输出端与正交信号补偿单元的输入端相连，正交信号补偿单元的输出端与正交信号差值细分计数单元的输入端相连。The output end of the quadruple-range polarized light unit is connected with the input end of the photoelectric signal conversion unit, the output end of the photoelectric signal conversion unit is connected with the input end of the signal pre-amplification and conditioning unit, and the output end of the signal pre-amplification and conditioning unit is connected with the input end of the signal pre-amplification and conditioning unit. The input end of the signal difference operation unit is connected, the output end of the signal difference operation unit is connected with the input end of the quadrature signal compensation unit, and the output end of the quadrature signal compensation unit is connected with the input end of the quadrature signal difference subdivision counting unit. 2.根据权利要求1所述的激光干涉测量信号处理装置，其特征在于：所述正交信号插值细分单元包括：2. The laser interferometric signal processing device according to claim 1, wherein the orthogonal signal interpolation and subdivision unit comprises: 可逆计算模块，采用正/反向并行计数的双向计数器，采用20位二进制补码，对正反向位移测量的整周期信号进行计数；The reversible calculation module adopts a bidirectional counter with forward/reverse parallel counting, and uses a 20-bit two's complement code to count the whole cycle signal measured by the forward and reverse displacement; 插值模块，对单周期信号进行16位连续插值，并实时输出插值数；Interpolation module, which performs 16-bit continuous interpolation on the single-period signal, and outputs the interpolation number in real time; 复位模块，当正交信号直流电平和幅度漂移相对误差大于5％时，矢量圆信号V7发生异常时，启动报警功能并对该模块进行及时复位。Reset module, when the relative error of the DC level and amplitude drift of the quadrature signal is greater than 5%, and the vector circle signal V7 is abnormal, the alarm function is activated and the module is reset in time. 3.根据权利要求1至2中任一项所述的激光干涉测量信号处理装置的信号细分方法，其特征在于：该方法包括下列顺序的步骤：3. The signal subdivision method of the laser interferometric signal processing device according to any one of claims 1 to 2, wherein the method comprises the steps of the following order: (1)初始化，通过四倍程偏振光单元的偏振分光镜以及λ/4波片对干涉条纹进行4倍程信号细分，再通过空间移相得到相位依次相差90°的四路干涉输出光强信号E1、E2、E3、E4；(1) Initialization, the interference fringes are subdivided by 4 times the signal through the polarization beam splitter of the quadruple-range polarizing light unit and the λ/4 wave plate, and then the four-way interference output light with a phase difference of 90° is obtained by spatial phase shifting. Strong signal E1, E2, E3, E4; (2)通过光电信号转换单元，采用差分零偏设计的四通道探测电路进行光电转换，分别将四倍程偏振光单元的四路干涉输出光强信号E1、E2、E3、E4转换为电流信号I1、I2、I3、I4；(2) Through the photoelectric signal conversion unit, a four-channel detection circuit designed with differential zero offset is used to perform photoelectric conversion, and the four-channel interference output light intensity signals E1, E2, E3, and E4 of the quadruple-range polarized light unit are respectively converted into current signals. I1, I2, I3, I4; (3)再通过信号前置放大调理单元，采用电流转化电压电路，将电流信号I1、I2、I3、I4转化为电压信号V1、V2、V3、V4，并通过放大电路、直流调节电路、低通滤波电路，对电压信号进行运算放大与调理；(3) Then through the signal pre-amplification and conditioning unit, the current conversion voltage circuit is used to convert the current signals I1, I2, I3, I4 into voltage signals V1, V2, V3, V4, and through the amplifier circuit, DC adjustment circuit, low Through the filter circuit, the voltage signal is operationally amplified and conditioned; (4)再通过信号差分运算单元，将V1、V2、V3、V4相位相反的两个干涉光信号通过加法电路消除信号中的直流分量，得到两个共模抑制比较好正交信号再将这两路差动干涉信号送入模拟电路进一步放大和调理，经过该单元装置中各级处理电路后，采用减法电路对相位相反的四路电压信号两两相减，即V1-V2，V3-V4，最终得到两路相位差为90°的正交电压信号V5和V6；(4) Then, through the signal differential operation unit, the two interfering optical signals with opposite phases of V1, V2, V3, and V4 are eliminated by the addition circuit to eliminate the DC component in the signal, and two orthogonal signals with better common mode suppression are obtained. The two differential interference signals are sent to the analog circuit for further amplification and conditioning. After passing through the various processing circuits in the unit device, the subtraction circuit is used to subtract the four voltage signals with opposite phases, namely V1-V2, V3-V4. , and finally obtain two quadrature voltage signals V5 and V6 with a phase difference of 90°; (5)再通过正交信号补偿单元，对处理后的两路正交电压信号V5和V6进行A/D高速转换后，加载正交矢量圆修正模型，进行高速实时自动修正和补偿，并将电压信号V5和V6合成为矢量信号V7；(5) Through the quadrature signal compensation unit, after performing A/D high-speed conversion on the processed two-way quadrature voltage signals V5 and V6, load the quadrature vector circle correction model, perform high-speed real-time automatic correction and compensation, and The voltage signals V5 and V6 are synthesized into a vector signal V7; (6)再通过正交信号插值细分计数单元，对周期信号进行计数的同时，对不足一个周期的信号进行插值；对正交矢量合成信号是否具备插值做判断，若不符合，自动修正后进行插值细分。(6) Through the orthogonal signal interpolation subdivision counting unit, while counting the periodic signals, interpolate the signals with less than one cycle; judge whether the orthogonal vector composite signal has interpolation, if not, it will be automatically corrected. Interpolate subdivisions. 4.根据权利要求3所述的激光干涉测量信号处理装置的信号细分方法，其特征在于：所述步骤(5)所述的正交矢量圆修正模型具体指：4. The signal subdivision method of the laser interferometric signal processing device according to claim 3, characterized in that: the orthogonal vector circle correction model described in the step (5) specifically refers to: 当两路正交信号存在非正交、非等幅时，矢量合成信号V7在X、Y轴方向分量表述为：When the two quadrature signals have non-orthogonal and unequal amplitudes, the components of the vector composite signal V7 in the X and Y axis directions are expressed as:
Figure FDA0003190037810000031
Figure FDA0003190037810000031
 其中，I'x为矢量信号V7在X轴方向分量、I'y为矢量信号V7在Y轴方向分量，α表示非正交误差；G为两路测量信号振幅的比值；p、q分别是两路测量信号的直流漂移大小；当α≠0、G≠1或p≠q时，合成的矢量圆信号是一个椭圆而非标准圆，此时椭圆方程与G、p、q的关系描述为：Wherein, I'x is the component of the vector signal V7 in the X-axis direction, I'y is the component of the vector signal V7 in the Y-axis direction, α represents the non-orthogonal error; G is the ratio of the amplitudes of the two measurement signals; p, q are respectively The DC drift of the two measurement signals; when α≠0, G≠1 or p≠q, the synthesized vector circle signal is an ellipse instead of a standard circle, and the relationship between the ellipse equation and G, p, q is described as :
Figure FDA0003190037810000032
Figure FDA0003190037810000032
 将(1-2)式简化为:Simplify (1-2) into:
Figure FDA0003190037810000033
Figure FDA0003190037810000033
 其中，R为椭圆方程的变半径，A、B、C、D、E分别为椭圆方程的不同系数，系数A＝R2cos2α-p2-G2q2–2Gpqsinα；系数B＝-G2；系数C＝-2Gsinα；系数D＝2p+2Gqsinα；系数E＝2G2q+2Gpsinα；Among them, R is the variable radius of the ellipse equation, A, B, C, D, and E are the different coefficients of the ellipse equation, respectively, coefficient A=R 2 cos 2 α-p 2 -G 2 q 2 -2Gpqsinα; coefficient B=- G 2 ; coefficient C=−2Gsinα; coefficient D=2p+2Gqsinα; coefficient E=2G 2 q+2Gpsinα; 通过多元线性回归法，分别计算求出系数A、B、C、D、E，得出α、G、R、p、q，如式(1-4)：Through the multiple linear regression method, the coefficients A, B, C, D, and E are calculated and obtained respectively, and α, G, R, p, and q are obtained, as shown in formula (1-4):
Figure FDA0003190037810000034
Figure FDA0003190037810000034
 通过补偿修正，矢量信号合成是一个标准圆矢量信号V7：Through compensation correction, the vector signal synthesis is a standard circular vector signal V7:
Figure FDA0003190037810000035
Figure FDA0003190037810000035
 5.根据权利要求3所述的激光干涉测量信号处理装置的信号细分方法，其特征在于：所述步骤(6)中的对正交矢量合成信号是否具备插值做判断，若不符合，自动修正后进行插值细分具体是指：5. the signal subdivision method of the laser interferometric signal processing device according to claim 3, is characterized in that: in the described step (6), to judge whether the orthogonal vector composite signal has interpolation, if it does not meet, automatically The interpolation subdivision after correction specifically refers to: (6a)首先启动判断，对原始信号的相位角正交度、直流电平、幅度漂移相对误差是否小于5％时进行判断，自动修正补偿使合成矢量圆信号V7为标准圆；(6a) Start judgment first, judge whether the relative error of the phase angle quadrature, DC level, and amplitude drift of the original signal is less than 5%, and automatically correct and compensate to make the synthetic vector circle signal V7 a standard circle; (6b)再通过20位二进制补码可逆计算电路，记录测量正反向整周期信号的计数N；(6b) Through the 20-bit two's complement reversible calculation circuit, record and measure the count N of the positive and negative integer periodic signals; (6c)然后以8M/S速率对非整周期信号进行16位插值采样，并对合成矢量圆信号V7的波形、振幅和相位分别进行插值采样，采用映射变换方式，通过细分算法对信号实现的200倍细分；(6c) Then perform 16-bit interpolation sampling on the non-integral periodic signal at a rate of 8M/S, and perform interpolation sampling on the waveform, amplitude and phase of the synthetic vector circle signal V7 respectively, adopt the mapping transformation method, and realize the signal through the subdivision algorithm. 200 times subdivision of ; (6d)最后通过合成四倍程偏振光单元的信号4倍细分和正交信号插值计数200倍细分，最终实现激光干涉位移测量系统的激光波长λ的800倍信号细分，使激光干涉位移测量系统分辨率达λ/800；(6d) Finally, by synthesizing the signal of the quadruple-range polarized light unit by 4 times of subdivision and the orthogonal signal interpolation count of 200 times of subdivision, the signal subdivision of 800 times of the laser wavelength λ of the laser interference displacement measurement system is finally realized, so that the laser interference The displacement measurement system has a resolution of λ/800; (6e)当正交信号相位正交度、直流电平和幅度漂移相对误差大于5％时，矢量圆信号V7将发生畸变，停止插值信号细分计数，重新复位激光干涉测量信号处理装置。(6e) When the relative error of the quadrature signal phase quadrature, DC level and amplitude drift is greater than 5%, the vector circle signal V7 will be distorted, stop the interpolation signal subdivision count, and reset the laser interferometry signal processing device.
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