Resonant low-light-level gyroscope based on variable optical fiber beam splitter and closed-loop control method of resonant low-light-level gyroscope

Abstract

The invention provides a resonant low-light-level gyroscope based on a variable optical fiber beam splitter and a closed-loop control method of the resonant low-light-level gyroscope, and belongs to the technical field of resonant optical gyroscopes. Comprising a laser, a variable optical fiber beam splitter, a phase modulator PMI, a phase modulator PMII, a circulator I, a circulator II, a 95% 2 * 2 coupler, a photoelectric detector PDI, a photoelectric detector PDII, an echo wall resonant cavity, a digital-analog interface, a digital system and an analog-digital interface. According to the invention, a double-closed-loop structure is realized by designing Schmidt type closed-loop switching, a linear region judgment scheme and automatic reset operation, and the linearity and dynamic range of ROG output are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of resonant optical gyroscopes, and in particular, relates to a resonant micro-optical gyroscope based on a variable optical fiber beam splitter and a closed-loop control method thereof. Background Art

[0002] Resonant Optic Gyro (ROG) is a sensor that uses the Sagnac effect to measure the angular velocity of a carrier in inertial space. It is widely used in many fields such as aviation, aerospace, navigation, and medicine. ROG can achieve higher detection accuracy while reducing volume and cost, while also reducing non-reciprocity errors caused by the environment. Driven by the rapid development of micro-satellites and micro-UAVs, miniaturized and high-precision ROG based on microcavities has become one of the research focuses. The Whispering Gallery Mode (WGM) resonant cavity is based on the principle of total internal reflection of light, which confines the incident light in the cavity and can achieve up to 10 9 The WGM resonant cavity has an ultra-high quality factor (Quality, Q) of the order of magnitude, and the larger the Q value, the higher the resolution of the gyroscope. At the same time, because the WGM resonant cavity has an extremely narrow spectral line width and an extremely small mode volume, it is very sensitive to external disturbances and is very likely to be used to realize a highly sensitive and high-precision micro ROG.

[0003] However, the ROG reported so far has not yet reached the theoretical accuracy due to the influence of noises such as Kerr effect, Shupe effect, polarization noise and backscattering noise. The Kerr effect and photothermal effect can be effectively suppressed by carefully controlling the incident light power, while the backscattering noise caused by defects on the cavity surface is usually suppressed by using a wide-spectrum light source to reduce the coherence length, or by using a narrow-linewidth light source using modulation and demodulation technology to suppress carrier or large frequency difference filtering. However, there is still residual backscattering noise mixed in the signal to be measured, and the influence of system delay and phase fluctuation on gyro sensitivity during the demodulation process is often ignored. Another time-division multiplexing suppression scheme that uses an optical switch to separate signal light and backscattered light can effectively improve the detection accuracy in theory, but it can only form a single closed-loop structure, resulting in poor linearity of the scale factor and small dynamic range of the ROG. The variable fiber beam splitter can act as an optical switch through voltage regulation, and can also realize the function of a 50:50 beam splitter to form a dual closed-loop structure, which is expected to improve the detection accuracy while realizing a small ROG. Summary of the invention

[0004] Aiming at the shortcomings of traditional ROG, such as large size and low precision, the present invention proposes a resonant micro-light gyroscope based on a variable fiber beam splitter and a closed-loop control method thereof, designs Schmidt-type closed-loop switching, a linear region judgment scheme and an automatic reset operation to realize a dual closed-loop structure, and improves the linearity and dynamic range of ROG output.

[0005] The present invention is achieved through the following technical solutions:

[0006] A resonant micro-optical gyroscope based on a variable optical fiber beam splitter:

[0007] The resonant micro-optical gyroscope comprises a laser, a variable optical fiber beam splitter, a phase modulator PMⅠ, a phase modulator PMⅡ, a circulator I, a circulator II, a 95% 2×2 coupler, a photodetector PDⅠ, a photodetector PDⅡ, a whispering gallery resonant cavity, a digital-to-analog interface, a digital system and an analog-to-digital interface;

[0008] The laser is connected to the variable fiber beam splitter and the digital-analog interface respectively, the variable fiber beam splitter is connected to the phase modulator PMⅠ and the phase modulator PMⅡ respectively, the phase modulator PMⅠ is connected to the circulator I and the digital-analog interface respectively, and the phase modulator PMⅡ is connected to the circulator II and the digital-analog interface respectively;

[0009] The circulator I is connected to the 95% 2×2 coupler and the photodetector PD I respectively, the circulator II is connected to the 95% 2×2 coupler and the photodetector PD II respectively, and the photodetector PD I and the photodetector PD II are both connected to the analog-to-digital interface;

[0010] The 95% 2×2 coupler is connected to the whispering gallery resonant cavity;

[0011] The digital-to-analog interface is connected with the analog-to-digital interface via a digital system.

[0012] Further, the digital-to-analog interface includes a digital-to-analog converter ADCⅠ, a digital-to-analog converter ADCⅡ, a digital-to-analog converter ADCⅢ and a digital-to-analog converter ADCⅣ;

[0013] The digital-to-analog converter ADCⅠ is connected to the variable optical fiber beam splitter;

[0014] The digital-to-analog converter ADCⅡ is connected to the phase modulator PMⅡ.

[0015] The digital-to-analog converter ADCⅢ is connected to the phase modulator PMⅠ.

[0016] The digital-to-analog converter ADCIV is connected to the laser.

[0017] Furthermore, the digital system includes an orthogonal demodulation module I, an orthogonal demodulation module II, a time division multiplexing and closed-loop switching module, a modulation signal generation module and a laser frequency locking control module;

[0018] The modulation signal generating module is connected to the digital-to-analog converter ADCⅡ and the digital-to-analog converter ADCⅢ respectively.

[0019] Subtracting the demodulated signals output by the orthogonal demodulation module I and the orthogonal demodulation module II to obtain two signals, which are used to achieve laser frequency locking and are used as gyro system outputs;

[0020] The laser frequency locking control module is connected with the subtraction signals of the orthogonal demodulation module I and the orthogonal demodulation module II.

[0021] Further, the analog-to-digital interface includes a low-pass filter I, a low-pass filter II, an analog-to-digital converter ADC I and an analog-to-digital converter ADC II;

[0022] The low-pass filter I is connected to the photodetector PD II and the analog-to-digital converter ADC I respectively; the low-pass filter II is connected to the photodetector PD I and the analog-to-digital converter ADC II respectively;

[0023] The analog-to-digital converter ADCⅠ is connected to the orthogonal demodulation module Ⅰ; the analog-to-digital converter ADCⅡ is connected to the orthogonal demodulation module Ⅱ.

[0024] A closed-loop control method for a resonant micro-optical gyroscope based on a variable fiber beam splitter:

[0025] The closed-loop control method is specifically as follows:

[0026] The light beam emitted by the laser is split by a variable optical fiber beam splitter, and the split light beams are respectively input to a phase modulator PMⅠ and a phase modulator PMⅡ for phase modulation;

[0027] The light beam modulated by the phase modulator PMⅠ enters the circulator Ⅰ, and the light beam modulated by the phase modulator PMⅡ enters the circulator Ⅱ. The light beams output by the circulator Ⅰ and the circulator Ⅱ are combined by a 95% 2×2 coupler and input into the whispering gallery resonator.

[0028] The light beam is reflected multiple times in the whispering gallery resonator. The light beam reflected from the whispering gallery resonator passes through the 95% 2×2 coupler again and enters circulator I and circulator II respectively.

[0029] The light beam entering the circulator I is converted into a voltage signal by the photodetector PD I, and then converted into a digital signal by the analog-to-digital converter ADC I after filtering out high-frequency noise through the low-pass filter I, and then sent to the orthogonal demodulation module I;

[0030] The light beam entering the circulator II is converted into a voltage signal by the photodetector PD II, and then converted into a digital signal by the analog-to-digital converter ADC II after filtering out high-frequency noise through the low-pass filter II, and then sent to the orthogonal demodulation module II;

[0031] The demodulation signals output by the orthogonal demodulation module I and the orthogonal demodulation module II are subtracted to obtain two signals, one of which is input to the laser frequency locking control module, and the other signal is output as the gyro system.

[0032] Furthermore, a signal input to the laser frequency locking control module is converted into a digital electrical signal by the digital-to-analog converter ADCⅣ, and the laser receives the digital electrical signal to adjust the output frequency.

[0033] At the same time, the signal generated by the laser frequency locking control module is given to the modulation signal generating module. The modulation signal generating module generates two sinusoidal electrical signals, which are respectively given to the phase modulator PMⅡ and the phase modulator PMⅠ through the digital-to-analog converter ADCⅡ and the digital-to-analog converter ADCⅢ; the phase modulator PMⅡ and the phase modulator PMⅠ adjust the phase according to the received signal.

[0034] Furthermore, the time division multiplexing and closed-loop switching module controls the variable fiber beam splitter through the digital-to-analog converter ADCⅠ, and realizes single-double closed-loop switching through a Schmidt-type judgment scheme and automatic reset operation according to the demodulated output voltage corresponding to the angular velocity sensed by the system.

[0035] Furthermore, the Schmidt type judgment scheme is specifically to set a low threshold voltage V set l , high threshold voltage V set_h And counter timing time Cnt_time;

[0036] When the demodulated output voltage exceeds the high threshold voltage V set_h When the timing reaches Cnt_time, the Flag signal is set to -1, and the time division multiplexing and closed-loop switching module puts the variable fiber beam splitter in a 50:50 optical coupler state through the analog-to-digital converter ADCⅠ. The modulation signal generation module superimposes the sawtooth wave frequency shift signal on the original sinusoidal wave modulation signal through the analog-to-digital converter ADCⅡ, and completes the second closed loop on the phase modulator PMⅡ, so that the system switches from a single closed-loop state to a dual closed-loop state.

[0037] When the demodulated output voltage is less than the low threshold voltage V set_l When the timing reaches Cnt_time, the Flag signal is set to +1, the time division multiplexing and closed-loop switching module puts the variable fiber beam splitter in the optical switch state through the analog-to-digital converter ADCⅠ, and the modulation signal generation module only performs sinusoidal wave modulation on the phase modulator PMⅡ through the analog-to-digital converter ADCⅡ, and the system switches from the dual closed-loop state to the single closed-loop state;

[0038] In the single closed-loop state, the backscattered light corresponding to the two light paths is collected respectively by the analog-to-digital converter ADCⅠ and the analog-to-digital converter ADCⅡ, and the collected value is updated in real time using the sliding mean. When the system switches to the dual closed-loop state, the corresponding mean is used as the error compensation factor to optimize the orthogonal demodulation output in the dual closed-loop state.

[0039] An electronic device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0040] A computer-readable storage medium is used to store computer instructions, and when the computer instructions are executed by a processor, the steps of the above method are implemented.

[0041] Beneficial effects of the present invention

[0042] The present invention adopts a high-Q WGM resonant cavity as the core sensitive device to reduce the volume and improve the sensitivity, uses a variable fiber beam splitter to perform time-division multiplexing to separate the backscattered light, and uses an orthogonal phase-locked amplifier to perform carrier suppression on the residual backscattered noise, effectively improving the ROG accuracy, sensitivity and robustness, and designs Schmidt-type closed-loop switching, a linear region judgment scheme and an automatic reset operation to realize a dual closed-loop structure, thereby improving the linearity and dynamic range of the ROG output.

[0043] By using a variable fiber beam splitter and phase modulator, the system can more accurately control the phase and intensity of the light beam, thereby improving measurement accuracy and sensitivity; the laser frequency locking control module and closed-loop control enable the frequency of the laser to be dynamically locked to the resonant frequency of the resonant cavity, improving the stability and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the resonant micro-light gyroscope system of the present invention.

[0045] Figure 2 It is a schematic diagram of Schmidt type closed loop switching and linear region judgment of the present invention.

[0046] Figure 3 is a schematic diagram of the automatic reset operation of the present invention, wherein Figure 3 -(a) is the reset frequency sweep scheme diagram, Figure 3 -(b) is the linear region judgment scheme diagram.

[0047] Among them are laser-1, variable fiber beam splitter-2, phase modulator PMⅠ-3, phase modulator PMⅡ-4, circulator I-5, circulator II-6, 95% 2×2 coupler-7, photodetector PDⅠ-8, photodetector PDⅡ-9, whispering gallery resonator-10, low-pass filter I-11, low-pass filter II-12, analog-to-digital converter ADCⅠ-13, analog-to-digital converter ADCⅡ-14, digital-to-analog converter ADCⅠ-15, digital-to-analog converter ADCⅡ-16, digital-to-analog converter ADCⅢ-17, digital-to-analog converter ADCⅣ-18, orthogonal demodulation module I-19, orthogonal demodulation module II-20. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0050] The present invention proposes a resonant micro-optical gyroscope based on a variable optical fiber beam splitter and a closed-loop control method thereof, which belongs to the technical field of resonant optical gyroscopes.

[0051] A resonant micro-optical gyroscope based on a variable optical fiber beam splitter, the resonant micro-optical gyroscope comprising a laser 1, a variable optical fiber beam splitter 2, a phase modulator PMⅠ3, a phase modulator PMⅡ4, a circulator Ⅰ5, a circulator Ⅱ6, a 95% 2×2 coupler 7, a photodetector PDⅠ8, a photodetector PDⅡ9, a whispering gallery resonant cavity 10, a digital-to-analog interface, a digital system and an analog-to-digital interface;

[0052] The laser 1 is connected to the variable fiber beam splitter 2 and the digital-analog interface respectively, the variable fiber beam splitter 2 is connected to the phase modulator PMⅠ3 and the phase modulator PMⅡ4 respectively, the phase modulator PMⅠ3 is connected to the circulator Ⅰ5 and the digital-analog interface respectively, and the phase modulator PMⅡ4 is connected to the circulator Ⅱ6 and the digital-analog interface respectively;

[0053] The circulator I5 is connected to the 95% 2×2 coupler 7 and the photodetector PDⅠ8 respectively, the circulator II6 is connected to the 95% 2×2 coupler 7 and the photodetector PDⅡ9 respectively, and the photodetector PDⅠ8 and the photodetector PDⅡ9 are both connected to the analog-to-digital interface;

[0054] The 95% 2×2 coupler 7 is connected to the whispering gallery resonant cavity 10;

[0055] The digital-to-analog interface is connected with the analog-to-digital interface via a digital system.

[0056] The digital-to-analog interface includes a digital-to-analog converter ADCⅠ15, a digital-to-analog converter ADCⅡ16, a digital-to-analog converter ADCⅢ17 and a digital-to-analog converter ADCⅣ18;

[0057] The digital-to-analog converter ADCⅠ15 is connected to the variable optical fiber beam splitter 2;

[0058] The digital-to-analog converter ADCⅡ16 is connected to the phase modulator PMⅡ4.

[0059] The digital-to-analog converter ADCⅢ17 is connected to the phase modulator PMⅠ3.

[0060] The digital-to-analog converter ADC IV 18 is connected to the laser 1 .

[0061] The digital system includes an orthogonal demodulation module I 19, an orthogonal demodulation module II 20, a time division multiplexing and closed-loop switching module 21, a modulation signal generation module 22 and a laser frequency locking control module 23;

[0062] The modulation signal generating module 22 is connected to the digital-to-analog converter ADCⅡ16 and the digital-to-analog converter ADCⅢ17 respectively.

[0063] The demodulation signals output by the orthogonal demodulation module I19 and the orthogonal demodulation module II20 are subtracted to obtain two signals, which are used to achieve laser frequency locking and are used as gyro system outputs.

[0064] The laser frequency locking control module 23 is connected to the subtraction signals of the orthogonal demodulation module I 19 and the orthogonal demodulation module II 20 .

[0065] The analog-to-digital interface includes a low-pass filter I 11, a low-pass filter II 12, an analog-to-digital converter ADC I 13 and an analog-to-digital converter ADC II 14;

[0066] The low-pass filter Ⅰ11 is connected to the photodetector PDⅡ9 and the analog-to-digital converter ADCⅠ13 respectively; the low-pass filter Ⅱ12 is connected to the photodetector PDⅠ8 and the analog-to-digital converter ADCⅡ14 respectively;

[0067] The analog-to-digital converter ADCⅠ13 is connected to the orthogonal demodulation module Ⅰ19; the analog-to-digital converter ADCⅡ14 is connected to the orthogonal demodulation module Ⅱ20.

[0068] The transmission of the photoelectric signal of the resonant micro-light gyroscope is specifically as follows: a tunable laser is connected to a variable optical fiber beam splitter, two outputs of the variable optical fiber beam splitter are respectively connected to a first phase modulator and a second phase modulator, the first phase modulator is connected to a circulator, and similarly, the second phase modulator is connected to the circulator, the No. 2 output end of the first circulator and the second circulator enters the WGM resonant cavity through a 95% coupler, the No. 3 output end of the first circulator and the second circulator is connected to photodetectors PDⅠ and PDⅡ, and the output signals of the photodetectors PDⅠ and PDⅡ are respectively connected to low-pass filters Ⅰ and Ⅱ, thereby entering the digital system.

[0069] The linearly polarized light emitted by the fiber laser 1 is divided into one beam or two beams of equal power after passing through the variable fiber beam splitter 2. The frequency of the optical signal is modulated into a sinusoidal signal after passing through the lithium niobate phase modulators 3 and 4, and then passes through the circulators 5 and 6 and enters the WGM resonant cavity 10 through the 95% 2x2 fiber coupler 7.

[0070] In the digital system, the modulation signal generating module 22 generates two sinusoidal electrical signals and gives them to the phase modulators PMⅠ and PMⅡ. The voltage signal is transmitted by the low-pass filter and sent to the orthogonal demodulation module through the ADC. The output difference generated by the orthogonal demodulation module is given to the laser frequency locking control module on the one hand, and the laser frequency locking control module generates a control signal and gives it to the laser tuning end, and on the other hand, it is used as the differential output of the gyroscope.

[0071] like Figure 1 The orange and blue parts propagate in the resonant cavity in the clockwise and counterclockwise directions respectively, and at the coupler, the light with different numbers of cycles in the clockwise and counterclockwise directions forms multi-beam interference. The light intensity signal formed by the interference is received by the photodetector through the circulator and collected by the analog-to-digital converter and converted into a digital electrical signal and enters the digital processing system in the FPGA.

[0072] After modulation and orthogonal demodulation of the signal, two demodulated quantities proportional to the frequency can be obtained clockwise and counterclockwise. The difference between the two demodulated quantities and the target value set at the resonance valley bottom is used as the error signal. After passing through the closed-loop controller, the laser frequency is closed-loop locked through the tuning end of the laser to lock it at the resonance frequency in the counterclockwise direction; according to the demodulated output voltage corresponding to the angular velocity sensitive to the system, the single-double closed-loop switching is realized through the Schmidt-type judgment scheme and automatic reset operation.

[0073] like Figure 2 As shown in the figure, the Schmidt type judgment scheme is as follows: Figure 2A low threshold voltage V is set in set_l and high threshold voltage V set_h And prevent narrowband noise and random noise from causing ringing. At the same time, the counter timing time Cnt_time is set to prevent pulse noise from causing the system's single and double closed-loop states to switch frequently;

[0074] The scheme works as follows: When the demodulated output voltage exceeds the high threshold voltage V set_h When the timing reaches Cnt_time, the Flag signal is set to -1, the time division multiplexing and closed-loop switching module 21 makes the variable fiber beam splitter 2 in a 50:50 optical coupler state through the analog-to-digital converter ADCⅠ15, and the modulation signal generation module 22 superimposes the sawtooth wave frequency shift signal on the original sinusoidal wave modulation signal through the analog-to-digital converter ADCⅡ16, completes the second closed loop on the phase modulator PMⅡ4, and switches the system from a single closed-loop state to a dual closed-loop state;

[0075] When the demodulated output voltage is less than the low threshold voltage V set_l And when the timing reaches Cnt_time, the Flag signal is set to +1, the time division multiplexing and closed-loop switching module 21 puts the variable fiber splitter 2 in the optical switch state through the analog-to-digital converter ADCⅠ15, and the modulation signal generating module 22 only performs sinusoidal wave modulation on the phase modulator PMⅡ4 through the analog-to-digital converter ADCⅡ16, and the system switches from the dual closed-loop state to the single closed-loop state.

[0076] In the single closed-loop state, the backscattered light corresponding to the two light paths is collected respectively by the analog-to-digital converter ADCⅠ15 and the analog-to-digital converter ADCⅡ16, and the collected value is updated in real time using the sliding mean. When the system switches to the dual closed-loop state, the corresponding mean is used as the error compensation factor to optimize the orthogonal demodulation output in the dual closed-loop state.

[0077] A closed-loop control method for a resonant micro-light gyroscope based on a variable optical fiber beam splitter, wherein the automatic reset method in the closed-loop control is specifically as follows: Figure 3 As shown in the figure, the left part (a) is the automatic reset operation, the upper figure is the resonance curve, and the lower figure is the orthogonal demodulation curve. The resonance curve is divided into five areas Ⅰ-Ⅴ according to the criteria P1 and P2. If the light intensity collected by the ADC is greater than P1 for a certain period of time, it is determined that the system is unlocked. The FPGA subtracts a FSR distance from the locking voltage through the laser locking control module. The new locking voltage will fall into any one of the five areas, but it can only be re-locked if it falls in area Ⅰ.

[0078] In area I, the frequency will be quickly swept with a larger step value until the light intensity collected by the ADC is less than P1; at this time, the system is considered to have entered area II, and the frequency will be carefully swept with a smaller step value. Only when the light intensity collected by the ADC is less than P2, and the demodulated output is considered to have entered the linear region through the judgment criteria P3 and P4, the system is considered to have entered area II and closed-loop control begins. If the new frequency-locking voltage falls in other areas, the frequency will be swept quickly until the light intensity collected by the ADC is greater than P1 for a certain period of time. At this time, the frequency-locking voltage is subtracted from the distance W to ensure that the new frequency-locking voltage falls in area I and complete the closed-loop control;

[0079] The right side (b) of the figure is the linear region judgment scheme. The criteria P3 and P4 with different voltage values ​​are set to prevent ringing caused by narrowband noise and random noise. A is the linear region judge. When the light intensity collected by the ADC is less than P1 and greater than P2, and the demodulation voltage is less than P3, the linear region judge A is set to 0, otherwise it is set to 1; when the light intensity collected by the ADC is less than P2, and the demodulation voltage is greater than P4, the linear region judge A is set to 1, otherwise it is set to 0; tap A to get A d0 , for A d0 Hit a beat and get an A d1 , through A d0 and A d1 The logical operation obtains the rising edge of A up and falling edge A down , only after collecting A up After collecting A again down , it is considered to have entered the linear region. After entering the linear region, A is prohibited from flipping. Only when the system takes a reset operation, A is released again to make a linear region judgment.

[0080] According to the resonance curve and the linear region of the orthogonal demodulation curve, the threshold value in the linear region of the orthogonal demodulation curve is specifically divided as follows: on the output curve graph, when the linearity does not increase in proportion with the increase of the horizontal axis frequency difference, the linear region low threshold voltage V set_l and high threshold voltage V set_h The corresponding value on the vertical axis.

[0081] An electronic device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0082] A computer-readable storage medium is used to store computer instructions, and when the computer instructions are executed by a processor, the steps of the above method are implemented.

[0083] The memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory, ROM, a programmable read-only memory, PROM, an erasable programmable read-only memory, EPROM, an electrically erasable programmable read-only memory, EEPROM, or a flash memory. The volatile memory may be a random access memory, RAM, which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory static RAM, SRAM, dynamic random access memory dynamic RAM, DRAM, synchronous dynamic random access memory synchronous DRAM, SDRAM, double data rate synchronous dynamic random access memory double data rate SDRAM, DDR SDRAM, enhanced synchronous dynamic random access memory enhanced SDRAM, ESDRAM, synchronous link dynamic random access memory synchlink DRAM, SLDRAM, and direct memory bus random access memory direct rambus RAM, DR RAM. It should be noted that memory of the methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0084] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center through a wired method such as coaxial cable, optical fiber, digital subscriber line digital subscriber line, DSL or wireless such as infrared, wireless, microwave, etc. to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium such as a floppy disk, a hard disk, a tape, an optical medium such as a high-density digital video disc digital video disc, DVD, or a semiconductor medium such as a solid state hard disk solid state disc, SSD, etc.

[0085] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software modules in a processor for execution. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0086] It should be noted that the processor in the embodiment of the present application can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiment can be completed by an integrated logic circuit of hardware in the processor or an instruction in the form of software. The above processor can be a general-purpose processor, a digital signal processor DSP, an application-specific integrated circuit ASIC, a field programmable gate array FPGA or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to perform, or the hardware and software modules in the decoding processor can be combined to perform. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0087] The above is a detailed introduction to a resonant micro-light gyroscope based on a variable fiber beam splitter and a closed-loop control method thereof proposed in the present invention, and the principles and implementation methods of the present invention are explained. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for a person skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A resonant micro-light gyroscope based on a variable optical fiber beam splitter, characterized in that: The resonant micro-optical gyroscope comprises a laser (1), a variable optical fiber beam splitter (2), a phase modulator PMⅠ (3), a phase modulator PMⅡ (4), a circulator I (5), a circulator II (6), a 95% 2×2 coupler (7), a photodetector PDⅠ (8), a photodetector PDⅡ (9), a whispering gallery resonant cavity (10), a digital-to-analog interface, a digital system and an analog-to-digital interface; The laser (1) is connected to a variable optical fiber beam splitter (2) and a digital-analog interface respectively, the variable optical fiber beam splitter (2) is connected to a phase modulator PMⅠ (3) and a phase modulator PMⅡ (4) respectively, the phase modulator PMⅠ (3) is connected to a circulator I (5) and a digital-analog interface respectively, and the phase modulator PMⅡ (4) is connected to a circulator II (6) and a digital-analog interface respectively; The circulator I (5) is connected to the 95% 2×2 coupler (7) and the photodetector PD I (8) respectively, the circulator II (6) is connected to the 95% 2×2 coupler (7) and the photodetector PD II (9) respectively, and the photodetector PD I (8) and the photodetector PD II (9) are both connected to the analog-to-digital interface; The 95% 2×2 coupler (7) is connected to the whispering gallery resonant cavity (10); The digital-to-analog interface is connected with the analog-to-digital interface via a digital system.

2. The resonant micro-light gyroscope according to claim 1, characterized in that: The digital-to-analog interface comprises a digital-to-analog converter ADCⅠ(15), a digital-to-analog converter ADCⅡ(16), a digital-to-analog converter ADCⅢ(17) and a digital-to-analog converter ADCⅣ(18); The digital-to-analog converter ADC I (15) is connected to the variable optical fiber beam splitter (2); The digital-to-analog converter ADCⅡ (16) is connected to the phase modulator PMⅡ (4). The digital-to-analog converter ADC III (17) is connected to the phase modulator PM I (3). The digital-to-analog converter ADCIV (18) is connected to the laser (1).

3. The resonant micro-light gyroscope according to claim 2, characterized in that: The digital system comprises an orthogonal demodulation module I (19), an orthogonal demodulation module II (20), a time division multiplexing and closed-loop switching module (21), a modulation signal generation module (22) and a laser frequency locking control module (23); The modulation signal generating module (22) is connected to the digital-to-analog converter ADC II (16) and the digital-to-analog converter ADC III (17) respectively. Subtracting the demodulated signals output by the orthogonal demodulation module I (19) and the orthogonal demodulation module II (20) to obtain two signals for realizing laser frequency locking and serving as gyro system output; The laser frequency locking control module (23) is connected to the subtraction signals of the orthogonal demodulation module I (19) and the orthogonal demodulation module II (20).

4. The resonant micro-light gyroscope according to claim 3, characterized in that: The analog-to-digital interface comprises a low-pass filter I (11), a low-pass filter II (12), an analog-to-digital converter ADC I (13) and an analog-to-digital converter ADC II (14); The low-pass filter I (11) is connected to the photodetector PD II (9) and the analog-to-digital converter ADC I (13) respectively; the low-pass filter II (12) is connected to the photodetector PD I (8) and the analog-to-digital converter ADC II (14) respectively; The analog-to-digital converter ADC I (13) is connected to the orthogonal demodulation module I (19); the analog-to-digital converter ADC II (14) is connected to the orthogonal demodulation module II (20).

5. A closed-loop control method for a resonant micro-optical gyroscope based on the variable optical fiber beam splitter according to any one of claims 1 to 4, characterized in that: The closed-loop control method is specifically as follows: The light beam emitted by the laser (1) is split by a variable optical fiber beam splitter (2), and the split light beams are respectively input into a phase modulator PMⅠ (3) and a phase modulator PMⅡ (4) for phase modulation; The light beam modulated by the phase modulator PMⅠ (3) enters the circulator Ⅰ (5), and the light beam modulated by the phase modulator PMⅡ (4) enters the circulator Ⅱ (6). The light beams output by the circulator Ⅰ (5) and the circulator Ⅱ (6) are combined by a 95% 2×2 coupler (7) and input into the whispering gallery resonant cavity (10); The light beam is reflected multiple times in the whispering gallery resonant cavity (10), and the light beam reflected from the whispering gallery resonant cavity (10) passes through the 95% 2×2 coupler (7) again, and enters the circulator I (5) and the circulator II (6) respectively; The light beam entering the circulator I (5) is converted into a voltage signal by the photodetector PD I (8), filtered out high-frequency noise by a low-pass filter I (11), and then converted into a digital signal by an analog-to-digital converter ADC I (13), and sent to an orthogonal demodulation module I (19); The light beam entering the circulator II (6) is converted into a voltage signal by the photodetector PD II (9), filtered out high-frequency noise by a low-pass filter II (12), and then converted into a digital signal by an analog-to-digital converter ADC II (14) and sent to an orthogonal demodulation module II (20); The demodulated signals output by the orthogonal demodulation module I (19) and the orthogonal demodulation module II (20) are subtracted to obtain two signals, one of which is input to the laser frequency locking control module (23) and the other is output as the gyro system.

6. The control method of the resonant micro-light gyroscope according to claim 5, characterized in that: A signal input to the laser frequency locking control module (23) is converted into a digital-to-analog converter ADC IV (18) is converted into a digital electrical signal, and the laser (1) receives the digital electrical signal to adjust the output frequency. At the same time, the signal generated by the laser frequency locking control module (23) is given to the modulation signal generating module (22), and the modulation signal generating module (22) generates two sinusoidal electrical signals, which are respectively given to the phase modulator PMⅡ (4) and the phase modulator PMⅠ (3) through the digital-to-analog converter ADCⅡ (16) and the digital-to-analog converter ADCⅢ (17); the phase modulator PMⅡ (4) and the phase modulator PMⅠ (3) adjust the phase according to the received signal.

7. The control method of the resonant micro-light gyroscope according to claim 6, characterized in that: The time division multiplexing and closed-loop switching module (21) controls the variable optical fiber beam splitter (2) through the digital-to-analog converter ADC I (15), and realizes single-double closed-loop switching through a Schmidt-type judgment scheme and an automatic reset operation according to the demodulated output voltage corresponding to the angular velocity sensed by the system.

8. The control method of the resonant micro-light gyroscope according to claim 7, characterized in that: The Schmidt type judgment scheme is specifically to set a low threshold voltage V set_l , high threshold voltage V set_h And counter timing time Cnt_time; When the demodulated output voltage exceeds the high threshold voltage V set_h When the timing reaches Cnt_time, the Flag signal is set to -1, the time division multiplexing and closed-loop switching module (21) puts the variable optical fiber beam splitter (2) in a 50:50 optical coupler state through the analog-to-digital converter ADCⅠ (15), and the modulation signal generation module (22) superimposes the sawtooth wave frequency shift signal on the original sinusoidal wave modulation signal through the analog-to-digital converter ADCⅡ (16), completes the second closed loop on the phase modulator PMⅡ (4), and switches the system from a single closed loop state to a dual closed loop state; When the demodulated output voltage is less than the low threshold voltage V set_l When the timing reaches Cnt_time, the Flag signal is set to +1, the time division multiplexing and closed-loop switching module (21) puts the variable optical fiber beam splitter (2) in an optical switch state through the analog-to-digital converter ADCⅠ (15), and the modulation signal generation module (22) performs sinusoidal wave modulation on the phase modulator PMⅡ (4) only through the analog-to-digital converter ADCⅡ (16), and the system switches from the dual closed-loop state to the single closed-loop state; In a single closed loop state, the analog-to-digital converter ADCⅠ(15) and the analog-to-digital converter ADCⅡ (16) The backscattered light corresponding to the two light paths is collected respectively, and the collected value is updated in real time using a sliding mean. When the system switches to a double closed-loop state, the corresponding mean is used as an error compensation factor to optimize the orthogonal demodulation output in the double closed-loop state.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 5 to 8 are implemented.

10. A computer-readable storage medium for storing computer instructions, characterized in that: When the computer instructions are executed by a processor, the steps of the method according to any one of claims 5 to 8 are implemented.

Images