Silicon photon gyroscope based on digital angular velocity injection and online self-calibration method thereof

Abstract

The invention provides a silicon photon gyroscope based on digital angular velocity injection and an on-line self-calibration method thereof, the silicon photon gyroscope digitalizes different angular velocities into equivalent phase modulation signals, the equivalent phase modulation signals are accurately controlled by an FPGA control module and loaded to a phase modulator electrode of an optical chip module, a virtual rotation effect is artificially generated, and the phase modulation signals are accurately controlled by the FPGA control module and loaded to the phase modulator electrode of the optical chip module. According to the method, the response output of the gyroscope system is excited, and then the scale factor and the zero offset are reversely derived by performing linear fitting on the input-output relationship, so that high-precision self-calibration without an external turntable is realized. According to the method, normal form transformation from passive measurement to active excitation-response analysis is realized, the method has the remarkable advantages of full independence, high precision, repeatability, low cost and the like, and the key technical problems that an existing silicon photon gyroscope depends on external rotary table calibration, parameters cannot be updated online, zero offset errors are large and the like are solved.

Description

Technical Field

[0001] This invention relates to the fields of optical inertial navigation and micro / nano optoelectronics, and particularly to a silicon photonic gyroscope based on digital angular velocity injection and its online self-calibration method. Background Technology

[0002] With advancements in integrated photonics, CMOS processes, and micro / nano fabrication technologies, silicon photonic gyroscopes (SPGs) have become an ideal alternative to traditional fiber optic gyroscopes (FOGs) and mechanical gyroscopes due to their advantages such as small size, light weight, low power consumption, cost reduction, and ease of mass production. Their working principle is based on the Sagnac effect: when the system rotates around its sensitive axis, two coherent beams propagating clockwise (CW) and counterclockwise (CCW) generate a non-reciprocal phase difference, which is proportional to the angular velocity.

[0003] On silicon photonics platforms, by integrating key optical components such as light sources, beam splitters, phase modulators, waveguide interferometers, and photodetectors onto a single chip, millimeter-sized fully integrated optical gyroscopes can be realized, achieving zero-bias stability of 0.01° / h, approaching tactical or even navigation-grade performance. In recent years, institutions such as Caltech, MIT, Tueindhoven, Tsinghua University, the Institute of Semiconductors of the Chinese Academy of Sciences, Huawei's 2012 Labs, and HiSilicon Semiconductor have successively conducted research and prototype development on silicon photonic gyroscopes. For example, in 2022, the Tsinghua University team reported a closed-loop SPG based on the SOI platform with a zero-bias stability of 0.008° / h; Huawei's 2012 Labs publicly announced its "Photonic Inertial Unit" project in 2023, exploring the application of SPGs in autonomous driving. However, most of these systems are designed for ground-based or mild environments, and still face problems such as large zero-bias drift, unstable scaling factors, and lack of self-calibration capabilities during long-term operation.

[0004] Currently, the calibration of silicon photonic gyroscopes mainly relies on high-precision turntables. This method has serious drawbacks, such as dependence on external equipment, long calibration cycle, environmental mismatch, inability to update online, and high cost. In addition, some studies have attempted to use the zero-velocity latch-up method for zero-bias self-calibration, but it cannot calibrate the scaling factor and has extremely high requirements for the static state, thus limiting its practicality. Summary of the Invention

[0005] This invention provides a silicon photonic gyroscope based on digital angular velocity injection and its online self-calibration method, which can solve the technical problems of existing silicon photonic gyroscopes that rely on external turntable calibration, cannot update parameters online, and have large zero-bias errors.

[0006] According to one aspect of the present invention, a silicon photonic gyroscope based on digital angular velocity injection is provided, comprising an optical chip module, a signal demodulation module, an FPGA control module, a digital-to-analog converter and driving module, a self-calibration processing unit, and a parameter storage and compensation unit;

[0007] The optical chip module is used in self-calibration mode to convert the corresponding preset digital angular velocity into a first interference electrical signal including a phase difference based on each analog driving voltage, and output it to the signal demodulation module; it is also used in measurement mode to convert the input angular velocity into a second interference electrical signal including a phase difference, and output it to the signal demodulation module.

[0008] The signal demodulation module is used to demodulate each first interference optical signal in self-calibration mode to obtain the corresponding first digital phase difference and output it to the FPGA control module; it is also used to demodulate the second interference optical signal in measurement mode to obtain the second digital phase difference and output it to the FPGA control module.

[0009] In self-calibration mode, the FPGA control module is used to preset a set of digital angular velocity sequences and output them sequentially to the digital-to-analog converter and drive module; it obtains the calculated digital angular velocity based on each first digital phase difference and outputs all preset digital angular velocities and all calculated digital angular velocities to the self-calibration processing unit; it is also used in measurement mode to obtain the angular velocity information before compensation based on the digital phase difference and output it to the parameter storage and compensation unit.

[0010] The digital-to-analog converter and drive module is used to obtain the corresponding analog drive voltage based on each preset digital angular velocity in self-calibration mode, and output it to the optical chip module in sequence.

[0011] The self-calibration processing unit is used to perform linear fitting on all preset digital angular velocities and all solved digital angular velocities in self-calibration mode to obtain calibration parameters, and output them to the parameter storage and compensation unit; wherein, the calibration parameters include scaling factor and zero bias;

[0012] The parameter storage and compensation unit is used to store calibration parameters in self-calibration mode; it is also used to compensate the angular velocity information before compensation based on the calibration parameters in measurement mode to obtain the angular velocity information after compensation.

[0013] Preferably, the optical chip module includes a laser, a beam splitter, an interference loop, a phase modulator, and a photodetector; the laser emits a laser beam which is split into two paths by the beam splitter and enters the interference loop; the two laser beams rotate clockwise and counterclockwise respectively within the interference loop, generating a Sagnac phase difference, and return to the phase modulator to form an interference optical signal; the photodetector converts the interference optical signal into an interference electrical signal and outputs it to the signal demodulation module.

[0014] According to another aspect of the present invention, a silicon photonic gyroscope based on digital angular velocity injection and its online self-calibration method are provided, the method comprising:

[0015] In self-calibration mode, a set of digital angular velocity sequences are preset in the FPGA control module and output sequentially to the digital-to-analog converter and drive module; each preset digital angular velocity corresponds to an equivalent phase offset, which is equivalent to the silicon photonic gyroscope rotating at the currently preset digital angular velocity.

[0016] The digital-to-analog converter and drive module obtains the corresponding analog drive voltage based on each preset digital angular velocity and outputs it sequentially to the optical chip module;

[0017] The optical chip module converts the corresponding preset digital angular velocity into a first interference electrical signal including the phase difference based on each analog driving voltage, and outputs it to the signal demodulation module;

[0018] The signal demodulation module demodulates each first interference optical signal to obtain the corresponding first digital phase difference, and outputs it to the FPGA control module;

[0019] The FPGA control module obtains the calculated digital angular velocity based on each first digital phase difference, and outputs all preset digital angular velocities and all calculated digital angular velocities to the self-calibration processing unit.

[0020] The self-calibration processing unit performs linear fitting on all preset digital angular velocities and all calculated digital angular velocities to obtain calibration parameters, which are then output to the parameter storage and compensation unit. The calibration parameters include the scaling factor and zero bias.

[0021] In measurement mode, the optical chip module converts the input angular velocity into a second interference electrical signal including the phase difference and outputs it to the signal demodulation module;

[0022] The signal demodulation module demodulates the second interference optical signal to obtain the second digital phase difference, and outputs it to the FPGA control module.

[0023] The FPGA control module obtains the angular velocity information before compensation based on the digital phase difference and outputs it to the parameter storage and compensation unit.

[0024] The parameter storage and compensation unit compensates for the angular velocity information before compensation based on the calibration parameters to obtain the angular velocity information after compensation.

[0025] Preferably, the equivalent phase offset is obtained by the following formula:

[0026]

[0027] In the formula, Δφ iLet be the equivalent phase offset corresponding to the i-th preset digital angular velocity, N be the number of interference loops within the optical chip module, A be the equivalent area of ​​the interference loops, λ be the operating wavelength of the optical chip module, c be the speed of light in vacuum, and Ω be the equivalent phase offset. i Let be the i-th preset digital angular velocity, i = 1, 2, ..., n, where n is the number of digital angular velocities in the preset digital angular velocity sequence.

[0028] Preferably, a set of digital angular velocity sequences Ω is preset. d It can be set to:

[0029] Ω d ={-500° / s,-200° / s,-100° / s,-50° / s,0° / s,50° / s,100° / s,200° / s,500° / s}

[0030] Preferably, the analog drive voltage is obtained by the following formula:

[0031]

[0032] in, Then V i =k m Ω i

[0033] In the formula, V i V is the analog drive voltage corresponding to the i-th preset digital angular velocity. π k is the preset half-wave voltage of the phase modulator within the optical chip module. m This is the proportionality coefficient.

[0034] Preferably, the compensated angular velocity information is obtained by the following formula:

[0035]

[0036] In the formula, Ω out For the compensated angular velocity information, To obtain the angular velocity information before compensation, K cal B is the scaling factor. cal It has zero bias.

[0037] By applying the technical solution of this invention, different angular velocities are digitized into equivalent phase modulation signals. These signals are then precisely controlled by an FPGA control module and applied to the phase modulator electrodes of the optical chip module, artificially generating a "virtual rotation" effect to excite the response output of the gyroscope system. Furthermore, by linearly fitting the input-output relationship, the scaling factor and zero bias are derived, achieving high-precision self-calibration without the need for an external turntable. This method realizes a paradigm shift from "passive measurement" to "active excitation-response analysis," offering significant advantages such as full autonomy, high precision, repeatability, and low cost. It solves key technical problems of existing silicon photonic gyroscopes, such as reliance on external turntable calibration, inability to update parameters online, and large zero-bias errors. Attached Figure Description

[0038] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0039] Figure 1 A schematic diagram of a silicon photonic gyroscope based on digital angular velocity injection according to an embodiment of the present invention is shown;

[0040] Figure 2 A flowchart of an online self-calibration method for a silicon photonic gyroscope based on digital angular velocity injection according to an embodiment of the present invention is shown;

[0041] Figure 3 A linear fitting diagram of a silicon photonic gyroscope provided according to an embodiment of the present invention is shown. Detailed Implementation

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0044] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0045] like Figure 1 As shown, the present invention provides a silicon photonic gyroscope based on digital angular velocity injection, including an optical chip module, a signal demodulation module, an FPGA control module, a digital-to-analog converter and driving module, a self-calibration processing unit, and a parameter storage and compensation unit;

[0046] The optical chip module is used in self-calibration mode to convert the corresponding preset digital angular velocity into a first interference electrical signal including a phase difference based on each analog driving voltage, and output it to the signal demodulation module; it is also used in measurement mode to convert the input angular velocity into a second interference electrical signal including a phase difference, and output it to the signal demodulation module.

[0047] The signal demodulation module integrates front-end signal processing circuitry (including amplification, demodulation, and ADC circuit units). In self-calibration mode, it demodulates each first interference optical signal to obtain the corresponding first digital phase difference and outputs it to the FPGA control module. In measurement mode, it demodulates the second interference optical signal to obtain the second digital phase difference and outputs it to the FPGA control module.

[0048] The FPGA control module is the main control unit of the system. In self-calibration mode, it presets a set of digital angular velocity sequences and outputs them sequentially to the digital-to-analog converter and drive module; it obtains the calculated digital angular velocity based on each first digital phase difference and outputs all preset digital angular velocities and all calculated digital angular velocities to the self-calibration processing unit; it is also used in measurement mode to obtain the angular velocity information before compensation based on the digital phase difference and output it to the parameter storage and compensation unit; in addition, the FPGA control module coordinates the timing of each module to achieve calibration triggering or compensation triggering.

[0049] The digital-to-analog converter and drive module is used to obtain the corresponding analog drive voltage based on each preset digital angular velocity in self-calibration mode, and output it sequentially to the phase modulator electrode of the optical chip module.

[0050] The self-calibration processing unit is used to perform linear fitting on all preset digital angular velocities and all solved digital angular velocities in self-calibration mode to obtain calibration parameters, and output them to the parameter storage and compensation unit; wherein, the calibration parameters include scaling factor and zero bias;

[0051] The parameter storage and compensation unit is used to store calibration parameters in self-calibration mode; it is also used to compensate the angular velocity information before compensation based on the calibration parameters in measurement mode to obtain the angular velocity information after compensation.

[0052] In this embodiment, the optical chip module integrates the optical path (including laser, beam splitter, interference loop, phase modulator, and photodetector) completed by the interferometric silicon photonic gyroscope to realize the Sagnac interference effect, convert the input angular velocity into optical phase difference, and output an interference electrical signal.

[0053] Specifically, the optical chip module includes a laser, a beam splitter, an interference loop, a phase modulator, and a photodetector. The laser emits a laser beam that is split into two paths by the beam splitter and enters the interference loop. The two laser beams rotate clockwise and counterclockwise within the interference loop, respectively, generating a Sagnac phase difference, and return to the phase modulator to form an interference optical signal. The photodetector converts the interference optical signal into an interference electrical signal and outputs it to the signal demodulation module.

[0054] This invention also provides a silicon photonic gyroscope based on digital angular velocity injection and its online self-calibration method, the method comprising:

[0055] In self-calibration mode, a set of digital angular velocity sequences are preset in the FPGA control module and output sequentially to the digital-to-analog converter and drive module; each preset digital angular velocity corresponds to an equivalent phase offset, which is equivalent to the silicon photonic gyroscope rotating at the currently preset digital angular velocity.

[0056] The digital-to-analog converter and drive module obtains the corresponding analog drive voltage based on each preset digital angular velocity and outputs it sequentially to the optical chip module;

[0057] The optical chip module converts the corresponding preset digital angular velocity into a first interference electrical signal including the phase difference based on each analog driving voltage, and outputs it to the signal demodulation module;

[0058] The signal demodulation module demodulates each first interference optical signal to obtain the corresponding first digital phase difference, and outputs it to the FPGA control module;

[0059] The FPGA control module obtains the calculated digital angular velocity based on each first digital phase difference, and outputs all preset digital angular velocities and all calculated digital angular velocities to the self-calibration processing unit.

[0060] The self-calibration processing unit performs linear fitting on all preset digital angular velocities and all calculated digital angular velocities to obtain calibration parameters, which are then output to the parameter storage and compensation unit. The calibration parameters include the scaling factor and zero bias.

[0061] In measurement mode, the optical chip module converts the input angular velocity into a second interference electrical signal including the phase difference and outputs it to the signal demodulation module;

[0062] The signal demodulation module demodulates the second interference optical signal to obtain the second digital phase difference, and outputs it to the FPGA control module.

[0063] The FPGA control module obtains the angular velocity information before compensation based on the digital phase difference and outputs it to the parameter storage and compensation unit.

[0064] The parameter storage and compensation unit compensates for the angular velocity information before compensation based on the calibration parameters to obtain the angular velocity information after compensation.

[0065] To gain a further understanding of the present invention, the following description is provided in conjunction with... Figure 2 and Figure 3 The present invention provides a detailed description of the silicon photonic gyroscope based on digital angular velocity injection and its online self-calibration method.

[0066] like Figure 2 The diagram shows the flowchart of the self-calibration method, which includes four steps: digital angular velocity modeling and storage, phase modulation signal generation, self-calibration execution, and parameter compensation.

[0067] (1) Digital angular velocity modeling and storage

[0068] The FPGA control module has a pre-set set of standardized digital angular velocity sequence Ω d Unit: ° / s, covering commonly used dynamic ranges and avoiding extrapolation errors.

[0069] Ω d ={-500° / s,-200° / s,-100° / s,-50° / s,0° / s,50° / s,100° / s,200° / s,500° / s}

[0070] Each angular velocity Ω i Corresponding to an equivalent phase offset Δφ i This is equivalent to a silicon photonic gyroscope rotating with respect to Ωi, and its size is derived by inversely using the Sagnac formula:

[0071]

[0072] In the formula, Δφ i Let be the equivalent phase offset corresponding to the i-th preset digital angular velocity, N be the number of interference loops within the optical chip module, A be the equivalent area of ​​the interference loops, λ be the operating wavelength of the optical chip module, c be the speed of light in vacuum, and Ω be the equivalent phase offset. i Let be the i-th preset digital angular velocity, i = 1, 2, ..., n, where n is the number of digital angular velocities in the preset digital angular velocity sequence.

[0073] 2. Phase Modulation Signal Generation

[0074] A driving voltage of amplitude V is implemented in the digital-to-analog conversion and driving module, and applied to the modulator electrode of the optical chip module to achieve an equivalent rotational speed input. The phase offset ΔΦ of the phase modulator is proportional to the driving voltage V.

[0075]

[0076] Therefore, the applied driving voltage is:

[0077]

[0078] Define the scaling factor:

[0079] Then V i =k m Ω i

[0080] In the formula, V i V is the analog drive voltage corresponding to the i-th preset digital angular velocity. π k is the preset half-wave voltage of the phase modulator within the optical chip module. m This is the proportionality coefficient.

[0081] According to the pre-stored Ω i and the calibrated k m Real-time calculation of V iIt is applied to the modulator electrodes through digital-to-analog conversion and DAC conversion of the driver module.

[0082] 3. Silicon photonic gyroscope output self-calibration

[0083] (1) After receiving the calibration trigger signal, the self-calibration processing unit enters the "self-calibration mode";

[0084] (2) The digital-to-analog conversion and drive module uses Ω d The standardized digital angular velocities are determined, thus yielding the outputs V1, V2, ..., V. n The voltage is applied to the modulator electrode, with each voltage application lasting for 1 second to ensure system stability.

[0085] (3) The FPGA control module obtains the output signal before gyroscope compensation based on the digital phase difference and records the output angular velocity corresponding to each standardized digital angular velocity.

[0086] (4) After receiving the calibration trigger signal, the self-calibration processing unit begins to establish an input-output data pair.

[0087] (5) In the self-calibration processing unit, the least squares method is used to perform linear fitting of the input-output data, and the fitting curve is as follows: Figure 3 As shown:

[0088]

[0089] (7) Obtain the scaling factor K of the silicon photonic gyroscope cal and zero bias B cal ;

[0090] (8) Update the parameter storage area in the parameter storage and compensation unit for subsequent measurement compensation.

[0091] 4. Obtain the output of the silicon photonic gyroscope after parameter compensation.

[0092] In the parameter storage and compensation unit, based on the output before gyroscope compensation... Combined with silicon photonic gyroscope scaling factor K cal and zero bias B cal The gyroscope compensation output is obtained as follows:

[0093]

[0094] In the formula, Ω out For the compensated angular velocity information, To obtain the angular velocity information before compensation, K cal B is the scaling factor. cal It has zero bias.

[0095] In summary, this invention provides a silicon photonic gyroscope based on digital angular velocity injection and its online self-calibration method. By pre-setting a digital angular velocity signal in an FPGA, mapping it, and then loading it onto the modulator electrodes to achieve virtual rotational excitation, a high-precision silicon photonic gyroscope system and its control method are achieved through closed-loop feedback to complete self-calibration. This system overcomes the technical bottleneck of traditional calibration relying on external turntables, and for the first time proposes a fully closed-loop self-calibration architecture of "digital angular velocity injection—equivalent phase excitation—output response fitting—parameter correction and compensation." It can achieve high-precision online calibration and compensation of key parameters such as gyroscope zero bias, scaling factor, and nonlinear error without relying on any external rotating equipment. This significantly improves the long-term stability, environmental adaptability, and engineering reliability of the silicon photonic gyroscope, making it suitable for applications with extremely high requirements for navigation accuracy and autonomy, such as satellites, drones, autonomous driving, and deep-sea exploration.

[0096] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0097] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0098] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A silicon photonic gyroscope based on digital angular velocity injection, characterized in that, It includes an optical chip module, a signal demodulation module, an FPGA control module, a digital-to-analog converter and drive module, a self-calibration processing unit, and a parameter storage and compensation unit; The optical chip module is used in self-calibration mode to convert the corresponding preset digital angular velocity into a first interference electrical signal including a phase difference based on each analog driving voltage, and output it to the signal demodulation module. It is also used in measurement mode to convert the input angular velocity into a second interference electrical signal including the phase difference and output it to the signal demodulation module; The signal demodulation module is used to demodulate each first interference optical signal in self-calibration mode to obtain the corresponding first digital phase difference and output it to the FPGA control module; it is also used to demodulate the second interference optical signal in measurement mode to obtain the second digital phase difference and output it to the FPGA control module. In self-calibration mode, the FPGA control module is used to preset a set of digital angular velocity sequences and output them sequentially to the digital-to-analog converter and drive module; it obtains the calculated digital angular velocity based on each first digital phase difference and outputs all preset digital angular velocities and all calculated digital angular velocities to the self-calibration processing unit. It is also used in measurement mode to obtain the angular velocity information before compensation based on the digital phase difference and output it to the parameter storage and compensation unit; The digital-to-analog converter and drive module is used to obtain the corresponding analog drive voltage based on each preset digital angular velocity in self-calibration mode, and output it to the optical chip module in sequence. The self-calibration processing unit is used to perform linear fitting on all preset digital angular velocities and all solved digital angular velocities in self-calibration mode to obtain calibration parameters, and output them to the parameter storage and compensation unit; wherein, the calibration parameters include scaling factor and zero bias; The parameter storage and compensation unit is used to store calibration parameters in self-calibration mode; it is also used to compensate the angular velocity information before compensation based on the calibration parameters in measurement mode to obtain the angular velocity information after compensation.

2. The silicon photonic gyroscope according to claim 1, characterized in that, The optical chip module includes a laser, a beam splitter, an interference ring, a phase modulator, and a photodetector. The laser emits a laser beam that is split into two paths by the beam splitter and enters the interference ring. The two laser beams rotate clockwise and counterclockwise respectively within the interference ring, generating a Sagnac phase difference, and then return to the phase modulator to form an interference light signal. The photodetector converts the interference optical signal into an interference electrical signal and outputs it to the signal demodulation module.

3. A silicon photonic gyroscope based on digital angular velocity injection and its online self-calibration method, characterized in that, The method includes: In self-calibration mode, a set of digital angular velocity sequences are preset in the FPGA control module and output sequentially to the digital-to-analog converter and drive module; each preset digital angular velocity corresponds to an equivalent phase offset, which is equivalent to the silicon photonic gyroscope rotating at the currently preset digital angular velocity. The digital-to-analog converter and drive module obtains the corresponding analog drive voltage based on each preset digital angular velocity and outputs it sequentially to the optical chip module; The optical chip module converts the corresponding preset digital angular velocity into a first interference electrical signal including the phase difference based on each analog driving voltage, and outputs it to the signal demodulation module; The signal demodulation module demodulates each first interference optical signal to obtain the corresponding first digital phase difference, and outputs it to the FPGA control module; The FPGA control module obtains the calculated digital angular velocity based on each first digital phase difference, and outputs all preset digital angular velocities and all calculated digital angular velocities to the self-calibration processing unit. The self-calibration processing unit performs linear fitting on all preset digital angular velocities and all calculated digital angular velocities to obtain calibration parameters, which are then output to the parameter storage and compensation unit. The calibration parameters include the scaling factor and zero bias. In measurement mode, the optical chip module converts the input angular velocity into a second interference electrical signal including the phase difference and outputs it to the signal demodulation module; The signal demodulation module demodulates the second interference optical signal to obtain the second digital phase difference, and outputs it to the FPGA control module. The FPGA control module obtains the angular velocity information before compensation based on the digital phase difference and outputs it to the parameter storage and compensation unit. The parameter storage and compensation unit compensates for the angular velocity information before compensation based on the calibration parameters to obtain the angular velocity information after compensation.

4. The method according to claim 3, characterized in that, The equivalent phase offset is obtained using the following formula: In the formula, Δφ i Let be the equivalent phase offset corresponding to the i-th preset digital angular velocity, N be the number of interference loops within the optical chip module, A be the equivalent area of ​​the interference loops, λ be the operating wavelength of the optical chip module, c be the speed of light in vacuum, and Ω be the equivalent phase offset. i Let be the i-th preset digital angular velocity, i = 1, 2, ..., n, where n is the number of digital angular velocities in the preset digital angular velocity sequence.

5. The method according to claim 3, characterized in that, A set of digital angular velocity sequences Ω is preset d It can be set to: Ω d ={-500° / s,-200° / s,-100° / s,-50° / s,0° / s,50° / s,100° / s,200° / s,500° / s} 6. The method according to claim 3, characterized in that, The analog drive voltage is obtained using the following formula: in, Then V i =k m Ω i In the formula, V i V is the analog drive voltage corresponding to the i-th preset digital angular velocity. π k is the preset half-wave voltage of the phase modulator within the optical chip module. m This is the proportionality coefficient.

7. The method according to claim 3, characterized in that, The compensated angular velocity information is obtained using the following formula: In the formula, Ω out For the compensated angular velocity information, To obtain the angular velocity information before compensation, K cal B is the scaling factor. cal It has zero bias.

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