A fiber optic gyroscope photoelectric conversion component and photoelectric conversion method

Abstract

This invention discloses a fiber optic gyroscope photoelectric conversion component and method. The fiber optic gyroscope photoelectric conversion component includes a photodiode G1, switches S1 and S2, a capacitor C1, and an amplifier D1. The positive terminal of photodiode G1 is connected to a bias voltage, and the negative terminal of photodiode G1 is connected to one end of switch S1. The other end of switch S1 is connected to the negative input terminal of amplifier D1. Switch S2 and capacitor C1 are connected in parallel, with one end connected to the negative input terminal of amplifier D1 and the other end connected to the output terminal of amplifier D1. The positive input terminal of amplifier D1 is connected to signal ground. The fiber optic gyroscope photoelectric conversion component uses a relatively small capacitance value to obtain a large gain, and the noise of the photodetector component can be suppressed by integrating the capacitance C1.

Description

Technical Field

[0001] This invention relates to the field of electronic technology, specifically to a fiber optic gyroscope photoelectric conversion component and photoelectric conversion method. Background Technology

[0002] Traditional fiber optic gyroscopes perform photoelectric conversion using a photodetector assembly, which includes a photodiode, a preamplifier, and peripheral circuitry. The preamplifier operates on the transimpedance principle. The positive terminal of photodiode G1 is connected to the bias voltage, and its negative terminal is connected to the negative input of preamplifier D1. One end of resistor R1 is connected to the negative input of amplifier D1, and the other end is connected to the output of amplifier D1. The positive input of amplifier D1 is connected to signal ground.

[0003] Photodiode G1 converts the interference light intensities P1 and P2 into currents I1 and I2, with a conversion coefficient of K. During the positive and negative half-cycles of the square wave, currents I1 and I2 flow through resistor R1 connected across the preamplifier, respectively, converting the current into voltages U1 and U2, thus completing the photoelectric conversion process. The resistance of resistor R1 is R, then...

[0004] U1=KRP0[1+cos(φ+π / 2)]

[0005] U2=KRP0[1+cos(φ-π / 2)]

[0006] Then, the phase difference φ is obtained by the difference ΔU between the positive and negative half-cycle voltages U1 and U2, and thus the angular velocity Ω is obtained.

[0007] To obtain a larger bandwidth and gain, R1 needs to be selected with a larger resistance value. However, the noise of the photodetector assembly is directly proportional to the resistance value. A larger resistance value will increase the noise of the photodetector assembly, ultimately affecting the accuracy of the rotational angular velocity calculated by the fiber optic gyroscope. Summary of the Invention

[0008] In view of this, the present invention provides a fiber optic gyroscope photoelectric conversion component and photoelectric conversion method, which can solve the technical problem of the conflict between improving bandwidth and gain and reducing noise in existing fiber optic gyroscope photoelectric conversion components.

[0009] To solve the above-mentioned technical problems, the present invention is implemented as follows.

[0010] A fiber optic gyroscope photoelectric conversion component, comprising:

[0011] Photodiode G1, switch S1, switch S2, capacitor C1, amplifier D1;

[0012] The positive terminal of photodiode G1 is connected to the bias voltage, the negative terminal of photodiode G1 is connected to one end of switch S1, and the other end of switch S1 is connected to the negative input terminal of amplifier D1; switch S2 and capacitor C1 are connected in parallel, one end of which is connected to the negative input terminal of amplifier D1, and the other end of which is connected to the output terminal of amplifier D1; the positive input terminal of amplifier D1 is connected to signal ground.

[0013] Preferably, the main control chip of the fiber optic gyroscope control system, which is independent of the fiber optic gyroscope photoelectric conversion component, generates a phase-modulated square wave as the control reference for the photoelectric conversion of the fiber optic gyroscope photoelectric conversion component. The period of the phase-modulated square wave is 2τ, where τ is the propagation time of the light wave in the closed optical path.

[0014] The present invention provides a photoelectric conversion method for a fiber optic gyroscope photoelectric conversion component, the photoelectric conversion method being based on the aforementioned fiber optic gyroscope photoelectric conversion component, the photoelectric conversion method comprising:

[0015] After the rising edge of the phase-modulated square wave arrives, switches S1 and S2 are simultaneously disconnected. The duration of the disconnection of switches S1 and S2 is longer than the spike noise width to avoid spike noise. During the period when switch S1 is disconnected, the fiber optic gyroscope control system, independent of the fiber optic gyroscope photoelectric conversion component, acquires the output voltage of amplifier D1 during the positive half-cycle of the phase-modulated square wave. After the output voltage acquisition is completed, switch S2 is closed to reset amplifier D1. Then, switch S2 is disconnected and switch S1 is closed simultaneously for a duration of t1. During the t1 time that switch S1 remains closed, photodiode G1 converts the interference light intensity into current I1, which charges capacitor C1. The first charging is completed when the falling edge of the phase-modulated square wave arrives.

[0016] Preferably, after the first charging is completed, switch S1 is opened, and the integrated voltage Up1 of capacitor C1 output by amplifier D1 at this time is collected. After the collection is completed, switch S2 is closed to reset amplifier D1. After the reset is completed, switch S2 is opened, and switch S1 is closed at the same time. The closing time of switch S1 is t2. During the time t2 when switch S1 is closed, photodiode G1 converts the interference light intensity into current I2. Current I2 charges capacitor C1. When the rising edge of the phase modulation square wave arrives, the second charging is completed.

[0017] Preferably, after the second charging is completed, switch S1 is turned off, and the C1 integral voltage Up2 output by amplifier D1 is collected. After the collection is completed, switch S2 is turned off to reset amplifier D1.

[0018] Preferably, the integrated voltages Up1 and Up2 of the amplifier D1 during the positive and negative half-cycles of the phase-modulated square wave are respectively:

[0019]

[0020]

[0021] Where C is the capacitance of the charging capacitor, K is the power-current conversion coefficient, P0 is the zero-position power, and φ is the phase difference;

[0022] If the charging times t1 and t2 are set to be equal, i.e., t1=t2=t, then the phase difference φ can be obtained through the difference ΔU between Up1 and Up2, and then the rotational angular velocity of the fiber optic gyroscope can be calculated.

[0023] Beneficial effects:

[0024] (1) This invention achieves photoelectric conversion through the principle of current integration, thus solving the problems of the prior art.

[0025] (2) The present invention uses a smaller capacitance value to obtain a larger gain, and the noise of the photodetector assembly can be suppressed by integrating the capacitance C1.

[0026] (3) The present invention improves the output accuracy of the photodetector assembly, thereby improving the accuracy of the rotational angular velocity calculated by the fiber optic gyroscope.

[0027] (4) The present invention is simple to implement and easy to execute. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the fiber optic gyroscope photoelectric conversion component provided by the present invention;

[0029] Figure 2 The schematic diagram of the timing of the phase-modulated square wave, switch S1, switch S2, and photoelectric conversion component output provided by the present invention. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] like Figures 1-2 As shown, the present invention proposes a fiber optic gyroscope photoelectric conversion component, which includes a photodiode G1, a switch S1, a switch S2, a capacitor C1, and an amplifier D1;

[0032] The positive terminal of photodiode G1 is connected to the bias voltage, the negative terminal of photodiode G1 is connected to one end of switch S1, and the other end of switch S1 is connected to the negative input terminal of amplifier D1; switch S2 and capacitor C1 are connected in parallel, one end of which is connected to the negative input terminal of amplifier D1, and the other end of which is connected to the output terminal of amplifier D1; the positive input terminal of amplifier D1 is connected to signal ground.

[0033] Furthermore, the main control chip of the fiber optic gyroscope control system, which is independent of the fiber optic gyroscope photoelectric conversion component, generates a phase-modulated square wave as the control reference for the photoelectric conversion of the fiber optic gyroscope photoelectric conversion component. The period of the phase-modulated square wave is 2τ.

[0034] In this embodiment, the phase-modulated square wave serves as the control reference for photoelectric conversion by the photoelectric conversion component, and is generated by the main control chip (including but not limited to FPGA and DSP) of the fiber optic gyroscope control system. The period of the phase-modulated square wave is 2τ, which is twice the propagation time τ of the light wave in the closed optical path.

[0035] The rising and falling edges of the phase-modulated square wave are the transition moments of the +π / 2 and -π / 2 modulation phase difference. The photoelectric conversion component will exhibit spike noise. This invention integrates the current converted by photodiode G1 within the positive and negative half-cycles of the phase-modulated square wave before the transition moment arrives, and collects the integrated voltage at the transition moment. Finally, it integrates the current converted by photodiode G1 at the end of the transition moment.

[0036] The present invention provides a photoelectric conversion method for a fiber optic gyroscope photoelectric conversion component, the photoelectric conversion method being based on the aforementioned fiber optic gyroscope photoelectric conversion component, the photoelectric conversion method comprising:

[0037] After the rising edge of the phase-modulated square wave arrives, switches S1 and S2 are simultaneously disconnected. The duration of the disconnection of switches S1 and S2 is longer than the spike noise width to avoid spike noise. During the period when switch S1 is disconnected, the fiber optic gyroscope control system, independent of the fiber optic gyroscope photoelectric conversion component, acquires the output voltage of amplifier D1 during the positive half-cycle of the phase-modulated square wave. After the output voltage acquisition is completed, switch S2 is closed to reset amplifier D1. Then, switch S2 is disconnected and switch S1 is closed simultaneously for a duration of t1. During the t1 time that switch S1 remains closed, photodiode G1 converts the interference light intensity into current I1, which charges capacitor C1. The first charging is completed when the falling edge of the phase-modulated square wave arrives.

[0038] In this embodiment, the first charging time is t1.

[0039] Furthermore, after the first charging is completed, switch S1 is opened, and the integrated voltage Up1 of capacitor C1 output by amplifier D1 at this time is collected. After the collection is completed, switch S2 is closed to reset amplifier D1. After the reset is completed, switch S2 is opened, and switch S1 is closed at the same time. The closing time of switch S1 is t2. During the time t2 when switch S1 is closed, photodiode G1 converts the interference light intensity into current I2. Current I2 charges capacitor C1. When the rising edge of the phase modulation square wave arrives, the second charging is completed.

[0040] In this embodiment, the second charging time is t2.

[0041] Furthermore, after the second charging is completed, switch S1 is disconnected, and the C1 integral voltage Up2 output by amplifier D1 is collected. After the collection is completed, switch S2 is closed to reset amplifier D1.

[0042] This completes one data collection cycle.

[0043] Furthermore, the integrated voltages Up1 and Up2 of the amplifier D1 during the positive and negative half-cycles of the phase-modulated square wave are respectively:

[0044]

[0045]

[0046] Where C is the capacitance of the charging capacitor, K is the power-current conversion coefficient, P0 is the zero-position power, and φ is the phase difference.

[0047] Furthermore, if the charging times t1 and t2 are set to be equal, i.e., t1=t2=t, then the phase difference φ can be obtained from the difference ΔU between Up1 and Up2, and then the rotational angular velocity of the fiber optic gyroscope can be calculated.

[0048] Right now

[0049] After obtaining the phase difference φ, the rotational angular velocity Ω of the fiber optic gyroscope can be calculated by φ = kΩ, where k is the proportionality coefficient between the rotational angular velocity and the phase difference.

[0050] The specific embodiments described above only illustrate the design principles of the present invention. The shapes and names of the components in this description may differ and are not limited. Therefore, those skilled in the art can modify or make equivalent substitutions to the technical solutions described in the foregoing embodiments; and these modifications and substitutions do not depart from the inventive spirit and technical solutions of the present invention, and should all fall within the protection scope of the present invention.

Claims

1. A photoelectric conversion method for a fiber optic gyroscope photoelectric conversion component, wherein the photoelectric conversion method is based on the fiber optic gyroscope photoelectric conversion component, characterized in that, The photoelectric conversion method includes: After the rising edge of the phase-modulated square wave arrives, switches S1 and S2 are simultaneously disconnected. The duration of the disconnection of switches S1 and S2 is longer than the spike noise width to avoid spike noise. During the period when switch S1 is disconnected, the fiber optic gyroscope control system, independent of the fiber optic gyroscope photoelectric conversion component, acquires the output voltage of amplifier D1 during the positive half-cycle of the phase-modulated square wave. After the output voltage acquisition is completed, switch S2 is closed to reset amplifier D1. Then, switch S2 is disconnected and switch S1 is closed simultaneously for a duration of t1. During the t1 time that switch S1 remains closed, photodiode G1 converts the interference light intensity into current I1, which charges capacitor C1. The first charging is completed when the falling edge of the phase-modulated square wave arrives. The fiber optic gyroscope photoelectric conversion component includes a photodiode G1, a switch S1, a switch S2, a capacitor C1, and an amplifier D1. The positive terminal of photodiode G1 is connected to the bias voltage, the negative terminal of photodiode G1 is connected to one end of switch S1, and the other end of switch S1 is connected to the negative input terminal of amplifier D1; switch S2 and capacitor C1 are connected in parallel, one end of which is connected to the negative input terminal of amplifier D1, and the other end of which is connected to the output terminal of amplifier D1; the positive input terminal of amplifier D1 is connected to signal ground. After the first charge is completed, switch S1 is opened, and the integrated voltage Up1 of capacitor C1 output by amplifier D1 is collected. After the collection is completed, switch S2 is closed to reset amplifier D1. After the reset is completed, switch S2 is opened, and switch S1 is closed at the same time. The closing time of switch S1 is t2. During the time t2 when switch S1 is closed, photodiode G1 converts the interference light intensity into current I2. Current I2 charges capacitor C1. When the rising edge of the phase modulation square wave arrives, the second charge is completed.

2. The photoelectric conversion method as described in claim 1, characterized in that, The main control chip of the fiber optic gyroscope control system, which is independent of the fiber optic gyroscope photoelectric conversion component, generates a phase-modulated square wave as the control reference for the photoelectric conversion of the fiber optic gyroscope photoelectric conversion component. The period of the phase-modulated square wave is 2τ, where τ is the propagation time of the light wave in the closed optical path.

3. The photoelectric conversion method as described in claim 2, characterized in that, After the second charging is completed, switch S1 is turned off, and the C1 integral voltage Up2 output by amplifier D1 is collected. After the collection is completed, switch S2 is closed to reset amplifier D1.

4. The photoelectric conversion method as described in claim 3, characterized in that, The integrated voltages Up1 and Up2 of the amplifier D1 during the positive and negative half-cycles of the phase-modulated square wave are respectively: in, This refers to the capacitance value of the charging capacitor. The power-to-current conversion factor, Zero power, Phase difference; If we set the charging times t1 and t2 to be equal, both being t, i.e., t1=t2=t, then the phase difference can be obtained through the difference ΔU between Up1 and Up2. Then, the rotational angular velocity of the fiber optic gyroscope is calculated.

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