阅读说明：本技术 一种单dac光纤陀螺y波导半波电压补偿系统 (Y waveguide half-wave voltage compensation system of single DAC (digital-to-analog converter) fiber-optic gyroscope ) 是由 张宇飞 赵亚飞 李勇 滕飞 刘保林 刘奇 张沛勇 王晓玲 孙丽 崔斌 何泽民 于 2019-08-22 设计创作，主要内容包括：一种单DAC光纤陀螺Y波导半波电压补偿系统,涉及光纤陀螺角速率测量技术领域；包括光电探测器、前放电路、A/D转换模块、闭环算法中央处理单元、D/A转换模块、驱动电路、光电调制器和光纤环；对外部光信号依次进行光电转换处理、隔直流、滤波、模数转换处理、闭环计算、数模转换、放大处理,生成Y波导调制信号；将Y波导调制信号发送至光电调制器；光电调制器根据Y波导调制信号对光纤环的光信号进行相位调制,使光信号产生相位差Φ<Sub>FB</Sub>；本发明采用了引入比例系数K进行Y波导半波电压的补偿方法,简单可靠地解决了光纤陀螺Y波导半波电压补偿问题。(A single DAC fiber-optic gyroscope Y waveguide half-wave voltage compensation system relates to the technical field of fiber-optic gyroscope angular rate measurement; the device comprises a photoelectric detector, a preamplifier circuit, an A/D conversion module, a closed-loop algorithm central processing unit, a D/A conversion module, a drive circuit, a photoelectric modulator and an optical fiber ring; carrying out photoelectric conversion processing, DC blocking, filtering, analog-to-digital conversion processing, closed-loop calculation, digital-to-analog conversion and amplification processing on an external optical signal in sequence to generate a Y waveguide modulation signal; sending the Y waveguide modulation signal to a photoelectric modulator; the photoelectric modulator modulates the phase of the optical signal of the optical fiber ring according to the Y waveguide modulation signal to enable the optical signal to generate a phase difference phi FB (ii) a The invention adopts the method of introducing the proportionality coefficient K to compensate the Y waveguide half-wave voltage, and simply and reliably solves the problem of Y waveguide half-wave voltage compensation of the fiber optic gyroscope.)

1. The utility model provides a single DAC fiber-optic gyroscope Y waveguide half-wave voltage compensation system which characterized in that: the device comprises a photoelectric detector, a preamplifier circuit, an A/D conversion module, a closed-loop algorithm central processing unit, a D/A conversion module, a drive circuit, a photoelectric modulator and an optical fiber ring;

fiber ring: acquiring an external optical signal, and transmitting the optical signal to a photoelectric detector through a broadcast-television modulator;

a photoelectric detector: receiving an optical signal transmitted from the optical fiber ring; performing photoelectric conversion processing on the optical signal to generate an electric signal, and sending the electric signal to a front-end amplifier circuit;

a front-end circuit: receiving an electrical signal transmitted from the photodetector; sequentially carrying out DC blocking and filtering treatment on the electric signals; generating a PIN electrical signal; sending the PIN electric signal to an A/D conversion module;

an A/D conversion module: receiving a PIN electric signal transmitted by a front discharge circuit; performing analog-to-digital conversion processing on the PIN electrical signal to generate a digital signal; sending the digital signal to a closed-loop algorithm central processing unit;

closed-loop algorithm central processing unit: receiving a digital signal transmitted by the A/D conversion module; performing closed-loop calculation on the digital signal to obtain a digital feedback quantity D_FB(ii) a Will digital feedback quantity D_FBSending the data to a D/A conversion module;

a D/A conversion module: receiving digital feedback quantity D transmitted from central processing unit of closed-loop algorithm_FB(ii) a To digital feedback quantity D_FBPerforming digital-to-analog conversion processing to generate a feedback electric signal; sending feedback electrical signals to the driveA circuit;

a drive circuit: receiving a feedback electric signal transmitted by the D/A conversion module, and amplifying the feedback electric signal to generate a Y waveguide modulation signal; sending the Y waveguide modulation signal to a photoelectric modulator;

the photoelectric modulator: receiving the Y waveguide modulation signal from the drive circuit, and modulating the phase of the optical signal of the optical fiber ring according to the Y waveguide modulation signal to generate a phase difference phi_FB。

2. The single-DAC fiber-optic gyroscope Y-waveguide half-wave voltage compensation system of claim 1, wherein: the Y waveguide modulation signal is a step wave signal.

3. The single-DAC fiber-optic gyroscope Y-waveguide half-wave voltage compensation system of claim 2, wherein: the specific method for performing closed-loop calculation on the digital signal by the closed-loop algorithm central processing unit comprises the following steps:

step one, establishing a fiber optic gyroscope factor K_iThe computational model of (2);

introducing a proportionality coefficient K into the fiber-optic gyroscope factor calculation model; varying the digital feedback quantity D_FB；

Establishing a simultaneous equation of a fiber-optic gyroscope factor calculation model;

step four, resolving a fiber optic gyroscope factor calculation model with a proportionality coefficient K introduced according to a simultaneous equation; obtaining the factor K of the fiber-optic gyroscope_iThe solution model of (2); and according to the factor K of the fiber-optic gyroscope_iSolution model acquisition implementation K_iA method of stabilization;

step five, calculating a proportionality coefficient K;

and step six, obtaining the adjusting method of the proportionality coefficient K according to the calculation formula of the proportionality coefficient K.

4. The single-DAC fiber-optic gyroscope Y-waveguide half-wave voltage compensation system of claim 3, wherein: in the first step, the factor K of the fiber-optic gyroscope_iIs calculated byThe model is as follows:

in the formula, D_outOutputting digital quantity for the optical fiber gyroscope;

Ω is the input angular rate;

D_FBthe digital feedback quantity of the fiber-optic gyroscope is obtained; d_FB＝D_out；

Φ_FBIs the phase difference of the optical signals.

5. The single-DAC fiber-optic gyroscope Y-waveguide half-wave voltage compensation system of claim 3, wherein: in the second step, after a proportionality coefficient K is introduced, the formula (1) is changed into:

in the formula, after a proportionality coefficient K is introduced, a digital feedback quantity D_FBIs KD_out(ii) a The output digital quantity of the fiber-optic gyroscope is still D_out。

6. The single-DAC fiber-optic gyroscope Y-waveguide half-wave voltage compensation system of claim 3, wherein: in the third step, the simultaneous equation is as follows:

wherein, pi is the optical phase modulation amount;

l is the length of the optical fiber ring;

d is the diameter of the optical fiber ring;

λ is the wavelength of the external light source;

c is the vacuum light speed;

V_πis a Y waveguide half-wave voltage;

n is the digit of the D/A conversion module;

V_fand outputting the modulation voltage corresponding to the full scale for the D/A conversion module.

7. The single-DAC fiber-optic gyroscope Y-waveguide half-wave voltage compensation system of claim 3, wherein: in the fourth step, the method for calculating the fiber-optic gyroscope factor calculation model with the introduced proportionality coefficient K comprises the following steps:

substituting the formula (3) and the formula (4) into the formula (2) to obtain the fiber-optic gyroscope factor K_iThe solution model of (2):

8. the Y waveguide half-wave voltage compensation system of the single DAC fiber optic gyroscope according to claim 3 or 7, wherein: obtaining implementation K according to equation (5)_iThe stabilizing method comprises the following steps: when the half-wave voltage V of the Y waveguide_πWhen changed, maintain V_fThe proportional coefficient K is correspondingly adjusted without changing, namely K is realized_iThe stability of (2).

9. The single-DAC fiber-optic gyroscope Y-waveguide half-wave voltage compensation system of claim 3, wherein: in the fifth step, the calculation method of the proportionality coefficient K is as follows:

in the formula, D_2πThe digital quantity is output when the step wave is reset.

10. The single-DAC fiber-optic gyroscope Y-waveguide half-wave voltage compensation system of claim 3, wherein: in the sixth step, the method for adjusting the proportionality coefficient K comprises the following steps:

according to the formula (6), byDigital quantity output D when resetting the step wave_2πThe adjustment of the comparative example coefficient K is realized.

Technical Field

The invention relates to the technical field of optical fiber gyroscope angular rate measurement, in particular to a Y waveguide half-wave voltage compensation system of a single DAC optical fiber gyroscope.

Background

The Y waveguide is an important optical element of the fiber-optic gyroscope and integrates the functions of a beam splitter, a polarizer and a modulator, wherein the modulator is used for bias modulation and realizing closed-loop feedback modulation. The Y waveguide half-wave voltage is an important parameter of the Y waveguide and is also a key index influencing the performance of the closed-loop fiber optic gyroscope.

The half-wave voltage of the Y waveguide phase modulator changes along with the temperature, and other electrical drifts exist at the same time, so that the scale factor performance of the gyroscope is influenced. For the occasions with higher requirements on the scale factor performance, a Y waveguide half-wave voltage compensation measure needs to be designed to compensate the influence of the drift of the Y waveguide along with factors such as temperature and the like on the scale factor performance of the fiber-optic gyroscope.

Generally, an auxiliary DA converter is added to a fiber-optic gyroscope detection circuit to build a closed-loop control loop. However, the above methods mainly have the following problems: for a miniaturized low-cost fiber-optic gyroscope, due to the layout space limitation of a detection circuit and the cost requirement, the construction based on an auxiliary DAC control loop is difficult to realize on hardware, and the use of the miniaturized low-cost fiber-optic gyroscope in a wide temperature range is seriously restricted.

Patent CN102253503A discloses a temperature compensation method for half-wave voltage of an integrated electro-optical phase modulator. A modulation voltage temperature compensation circuit is constructed by using a thermistor, the input voltage is a modulation voltage before compensation, the output voltage is a modulation voltage after compensation, the modulation voltage is loaded on an electrode of the integrated electro-optic phase modulator, and the temperature characteristic of half-wave voltage of the integrated electro-optic phase modulator is compensated, so that the modulation stability of the integrated electro-optic phase modulator is improved, the phase drift is reduced, and when the modulation voltage temperature compensation circuit is applied to a fiber optic gyroscope, the stability of a scale factor can be improved. The invention realizes effective compensation of the half-wave voltage temperature characteristic of the integrated electro-optic phase modulator on hardware, has stable and reliable functions and effectively reduces the phase drift of the integrated electro-optic phase modulator. However, the compensation scheme proposed in the patent uses a thermistor to construct a modulation voltage temperature compensation circuit, which is different from the software compensation scheme proposed in the patent.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a single DAC fiber-optic gyroscope Y waveguide half-wave voltage compensation system.

The above purpose of the invention is realized by the following technical scheme:

a Y waveguide half-wave voltage compensation system of a single DAC (digital-to-analog converter) fiber-optic gyroscope comprises a photoelectric detector, a preamplifier circuit, an A/D (analog-to-digital) conversion module, a closed-loop algorithm central processing unit, a D/A conversion module, a drive circuit, a photoelectric modulator and a fiber-optic ring;

fiber ring: acquiring an external optical signal, and transmitting the optical signal to a photoelectric detector through a broadcast-television modulator;

a photoelectric detector: receiving an optical signal transmitted from the optical fiber ring; performing photoelectric conversion processing on the optical signal to generate an electric signal, and sending the electric signal to a front-end amplifier circuit;

a front-end circuit: receiving an electrical signal transmitted from the photodetector; sequentially carrying out DC blocking and filtering treatment on the electric signals; generating a PIN electrical signal; sending the PIN electric signal to an A/D conversion module;

an A/D conversion module: receiving a PIN electric signal transmitted by a front discharge circuit; performing analog-to-digital conversion processing on the PIN electrical signal to generate a digital signal; sending the digital signal to a closed-loop algorithm central processing unit;

closed-loop algorithm central processing unit: receiving a digital signal transmitted by the A/D conversion module; performing closed-loop calculation on the digital signal to obtain a digital feedback quantity D_FB(ii) a Will digital feedback quantity D_FBSending the data to a D/A conversion module;

a D/A conversion module: receiving digital feedback quantity D transmitted from central processing unit of closed-loop algorithm_FB(ii) a To digital feedback quantity D_FBPerforming digital-to-analog conversion processing to generate a feedback electric signal; sending the feedback electrical signal to a driving circuit;

a drive circuit: receiving a feedback electric signal transmitted by the D/A conversion module, and amplifying the feedback electric signal to generate a Y waveguide modulation signal; sending the Y waveguide modulation signal to a photoelectric modulator;

the photoelectric modulator: receiving the Y waveguide modulation signal from the drive circuit, and modulating the phase of the optical signal of the optical fiber ring according to the Y waveguide modulation signal to generate a phase difference phi_FB。

In the above single DAC fiber optic gyroscope Y waveguide half-wave voltage compensation system, the Y waveguide modulation signal is a step wave signal.

In the above-mentioned single DAC fiber optic gyroscope Y waveguide half-wave voltage compensation system, the specific method for the closed-loop algorithm central processing unit to perform closed-loop calculation on the digital signal includes the following steps:

step one, establishing a fiber optic gyroscope factor K_iThe computational model of (2);

introducing a proportionality coefficient K into the fiber-optic gyroscope factor calculation model; varying the digital feedback quantity D_FB；

Establishing a simultaneous equation of a fiber-optic gyroscope factor calculation model;

step four, resolving a fiber optic gyroscope factor calculation model with a proportionality coefficient K introduced according to a simultaneous equation; to obtain lightFactor K of fiber-optic gyroscope_iThe solution model of (2); and according to the factor K of the fiber-optic gyroscope_iSolution model acquisition implementation K_iA method of stabilization;

step five, calculating a proportionality coefficient K;

and step six, obtaining the adjusting method of the proportionality coefficient K according to the calculation formula of the proportionality coefficient K.

In the above-mentioned single DAC fiber-optic gyroscope Y-waveguide half-wave voltage compensation system, in the first step, the fiber-optic gyroscope factor K_iThe calculation model of (a) is:

in the formula, D_outOutputting digital quantity for the optical fiber gyroscope;

Ω is the input angular rate;

D_FBthe digital feedback quantity of the fiber-optic gyroscope is obtained; d_FB＝D_out；

Φ_FBIs the phase difference of the optical signals.

In the above half-wave voltage compensation system for Y waveguide of single DAC fiber optic gyroscope, in the second step, after introducing the proportionality coefficient K, the formula (1) becomes:

in the formula, after a proportionality coefficient K is introduced, a digital feedback quantity D_FBIs KD_out(ii) a The output digital quantity of the fiber-optic gyroscope is still D_out。

In the above half-wave voltage compensation system for Y waveguide of single DAC fiber-optic gyroscope, in the third step, the simultaneous equation is:

wherein, pi is the optical phase modulation amount;

l is the length of the optical fiber ring;

d is the diameter of the optical fiber ring;

λ is the wavelength of the external light source;

c is the vacuum light speed;

V_πis a Y waveguide half-wave voltage;

n is the digit of the D/A conversion module;

V_fand outputting the modulation voltage corresponding to the full scale for the D/A conversion module.

In the above single DAC fiber optic gyroscope Y waveguide half-wave voltage compensation system, in the fourth step, the method for calculating the fiber optic gyroscope factor calculation model with the introduced proportionality coefficient K is as follows:

substituting the formula (3) and the formula (4) into the formula (2) to obtain the fiber-optic gyroscope factor K_iThe solution model of (2):

in the Y waveguide half-wave voltage compensation system of the single DAC fiber-optic gyroscope, the K is realized according to the formula (5)_iThe stabilizing method comprises the following steps: when the half-wave voltage V of the Y waveguide_πWhen changed, maintain V_fThe proportional coefficient K is correspondingly adjusted without changing, namely K is realized_iThe stability of (2).

In the above single DAC fiber optic gyroscope Y waveguide half-wave voltage compensation system, in the fifth step, the calculation method of the proportionality coefficient K is as follows:

in the formula, D_2πThe digital quantity is output when the step wave is reset.

In the above single DAC fiber optic gyroscope Y waveguide half-wave voltage compensation system, in the sixth step, the adjusting method of the proportionality coefficient K is as follows:

digital quantity output D by resetting the step wave according to equation (6)_2πIs prepared byAnd adjusting the comparative example coefficient K.

Compared with the prior art, the invention has the following advantages:

(1) on the premise of not using an auxiliary DAC hardware circuit, the invention provides a compensation method for introducing a proportionality coefficient K to carry out Y waveguide half-wave voltage by fully utilizing the use mode of a2pi reset voltage corresponding to a non-full code;

(2) the invention is realized by pure coding, avoids the adoption of hardware resources such as DAC and the like, reduces the circuit complexity, has easy realization of a compensation algorithm, good repeatability of a compensation result, and is convenient, novel and unique to realize;

(3) the required Y waveguide compensation scheme can be easily obtained by calculating according to the ADC and DAC digits of different fiber-optic gyroscopes; and the adaptability is strong.

Drawings

FIG. 1 is a schematic diagram of a Y-waveguide half-wave voltage compensation system according to the present invention;

FIG. 2 is a detailed design diagram of a Y-waveguide half-wave voltage compensation module according to an embodiment;

fig. 3 is a schematic diagram of the detection process of the reset error of embodiment 2 pi.

Detailed Description

The invention is described in further detail below with reference to the following figures and specific examples:

the invention provides a Y waveguide half-wave voltage compensation system of a single-DAC (digital-to-analog converter) fiber-optic gyroscope, wherein a fiber-optic gyroscope detection circuit in the system does not need to be additionally provided with an auxiliary DAC (digital-to-analog converter) -based hardware circuit, the circuit complexity is reduced, and the digital feedback quantity D is used_FBMultiplying by a proportionality coefficient K, by adjusting the corresponding digital quantity D at 2pi reset_2πAnd K is adjusted, so that the compensation of the half-wave voltage of the Y waveguide is completed.

As shown in fig. 1, which is a schematic diagram of a Y waveguide half-wave voltage compensation system, it can be known that a single DAC fiber-optic gyroscope Y waveguide half-wave voltage compensation system includes a photodetector, a preamplifier, an a/D conversion module, a closed-loop algorithm central processing unit, a D/a conversion module, a driving circuit, a photoelectric modulator, and a fiber-optic ring;

fiber ring: acquiring an external optical signal, and transmitting the optical signal to a photoelectric detector through a broadcast-television modulator;

a photoelectric detector: receiving an optical signal transmitted from the optical fiber ring; performing photoelectric conversion processing on the optical signal to generate an electric signal, and sending the electric signal to a front-end amplifier circuit;

a front-end circuit: receiving an electrical signal transmitted from the photodetector; sequentially carrying out DC blocking and filtering treatment on the electric signals; generating a PIN electrical signal; sending the PIN electric signal to an A/D conversion module;

an A/D conversion module: receiving a PIN electric signal transmitted by a front discharge circuit; performing analog-to-digital conversion processing on the PIN electrical signal to generate a digital signal; sending the digital signal to a closed-loop algorithm central processing unit;

closed-loop algorithm central processing unit: receiving a digital signal transmitted by the A/D conversion module; performing closed-loop calculation on the digital signal to obtain a digital feedback quantity D_FB(ii) a Will digital feedback quantity D_FBSending the data to a D/A conversion module;

the specific method for performing closed-loop calculation on the digital signal by the closed-loop algorithm central processing unit comprises the following steps:

step one, establishing a fiber optic gyroscope factor K_iThe computational model of (2);

factor K of fiber optic gyroscope_iThe calculation model of (a) is:

in the formula, D_outOutputting digital quantity for the optical fiber gyroscope;

Ω is the input angular rate;

D_FBthe digital feedback quantity of the fiber-optic gyroscope is obtained; d_FB＝D_out；

Φ_FBIs the phase difference of the optical signals.

Introducing a proportionality coefficient K into the fiber-optic gyroscope factor calculation model; varying the digital feedback quantity D_FB；

After introducing the proportionality coefficient K, equation (1) becomes:

in the formula, a proportionality coefficient K is introduced, so that the digital quantity output is K2 when the step wave is reset^NThe peak value of the step wave is KV_fDigital feedback quantity D_FBIs KD_out(ii) a The output digital quantity of the fiber-optic gyroscope is still D_outWhen the half-wave voltage of the Y waveguide changes, V_fThe stability of the scale factor can be ensured by adjusting the proportionality coefficient K without changing.

Establishing a simultaneous equation of a fiber-optic gyroscope factor calculation model;

the simultaneous equations are:

wherein, pi is the optical phase modulation amount;

l is the length of the optical fiber ring;

d is the diameter of the optical fiber ring;

λ is the wavelength of the external light source;

c is the vacuum light speed;

V_πis a Y waveguide half-wave voltage;

n is the digit of the D/A conversion module;

V_fand outputting the modulation voltage corresponding to the full scale for the D/A conversion module.

Step four, resolving a fiber optic gyroscope factor calculation model with a proportionality coefficient K introduced according to a simultaneous equation; obtaining the factor K of the fiber-optic gyroscope_iThe solution model of (2); and according to the factor K of the fiber-optic gyroscope_iSolution model acquisition implementation K_iA method of stabilization;

the method for calculating the fiber-optic gyroscope factor calculation model with the introduced proportionality coefficient K comprises the following steps:

substituting the formula (3) and the formula (4) into the formula (2) to obtain the factor of the fiber-optic gyroscopeK_iThe solution model of (2):

obtaining implementation K according to equation (5)_iThe stabilizing method comprises the following steps: when the half-wave voltage V of the Y waveguide_πWhen changed, maintain V_fThe proportional coefficient K is correspondingly adjusted without changing, namely K is realized_iThe stability of (2).

Step five, calculating a proportionality coefficient K;

the calculation method of the proportionality coefficient K comprises the following steps:

in the formula, D_2πThe digital quantity is output when the step wave is reset.

And step six, obtaining the adjusting method of the proportionality coefficient K according to the calculation formula of the proportionality coefficient K. The adjustment of the proportionality coefficient K can be realized by adjusting the digital quantity corresponding to the 2pi reset.

The method for adjusting the proportionality coefficient K comprises the following steps:

digital quantity output D by resetting the step wave according to equation (6)_2πThe adjustment of the comparative example coefficient K is realized.

A D/A conversion module: receiving digital feedback quantity D transmitted from central processing unit of closed-loop algorithm_FB(ii) a To digital feedback quantity D_FBPerforming digital-to-analog conversion processing to generate a feedback electric signal; sending the feedback electrical signal to a driving circuit;

a drive circuit: receiving a feedback electric signal transmitted by the D/A conversion module, and amplifying the feedback electric signal to generate a Y waveguide modulation signal; the Y waveguide modulation signal is a step wave signal. And sending the Y waveguide modulation signal to the photoelectric modulator.

The photoelectric modulator: receiving the Y waveguide modulation signal from the drive circuit, and modulating the phase of the optical signal of the optical fiber ring according to the Y waveguide modulation signal to generate a phase difference phi_FB。