CN110455271B

CN110455271B - Optical fiber gyroscope

Info

Publication number: CN110455271B
Application number: CN201910897573.1A
Authority: CN
Inventors: 赖志林; 王振兴
Original assignee: Shenzhen Changmaoxiang Electronics Co ltd
Current assignee: Shenzhen Changmaoxiang Electronics Co ltd
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2024-05-31
Anticipated expiration: 2039-09-20
Also published as: CN110455271A

Abstract

The application provides an optical fiber gyroscope, which comprises a controller, a light emitting device, an optical fiber ring, a light receiving device and a data output interface, wherein the controller is used for generating a radio frequency modulation signal and a local oscillation signal; the light emitting device is electrically connected with the controller and is used for emitting light signals according to the modulation signals generated based on the radio frequency modulation signals; the optical fiber ring is optically coupled with the light emitting device and the light receiving device respectively and is used for transmitting optical signals to the light receiving device; the light receiving device is electrically connected with the controller and used for receiving the local oscillation signal, converting the optical signal received from the optical fiber loop into an electric signal, mixing the electric signal with the local oscillation signal to form a mixed signal, and feeding the mixed signal back to the controller; the controller is also used for calculating the optical path difference based on the mixing signal and obtaining the rotation angular velocity; the data output interface is used for outputting the rotation angular velocity. The optical fiber gyroscope of the application does not need an integrated optical modulator of a Y waveguide, can reduce the cost and is beneficial to popularization of the optical fiber gyroscope.

Description

Optical fiber gyroscope

Technical Field

The application relates to the field of gyroscopes, in particular to an optical fiber gyroscope.

Background

The fiber optic gyroscope is an angular rate measuring instrument developed based on the Sagnac effect, has the technical advantages of simple structure, impact resistance and large dynamic range, has the use effect of long service life and high reliability, and is widely applied to various fields of aerospace, robot control, petroleum coal exploitation and the like.

Currently, the optical path part of the fiber optic gyroscope on the market mainly comprises 5 devices, namely a light source, a fiber optic coupler, a Y-waveguide integrated optical modulator, a fiber optic ring and a photoelectric detector. However, since the Y-waveguide integrated optical modulator is relatively expensive, the fiber optic gyroscope is relatively expensive and cannot be popularized for civilian use.

Disclosure of Invention

The embodiment of the application aims to provide an optical fiber gyroscope which is used for realizing the measurement of a rotation angle by adopting a difference frequency phase measurement principle and replacing a relatively expensive Y-waveguide integrated optical modulator, thereby being beneficial to civilian popularization of the optical fiber gyroscope.

An optical fiber gyroscope comprises a controller, a light emitting device, a first optical fiber ring, a second optical fiber ring, a first light receiving device and a second light receiving device; the controller is used for generating a radio frequency modulation signal and a local oscillation signal; the light emitting device is electrically connected with the controller and is used for emitting light signals according to the modulation signals generated based on the radio frequency modulation signals; the first optical fiber ring is arranged between the light emitting device and the first light receiving device and is used for transmitting the optical signal emitted by the light emitting device to the first light receiving device; the second optical fiber ring is arranged between the light emitting device and the second light receiving device and is used for transmitting the optical signal emitted by the light emitting device to the second light receiving device; the first light receiving device is electrically connected with the controller and is used for receiving the local oscillation signal, converting the optical signal received from the first optical fiber loop into a first electric signal, mixing the first electric signal with the local oscillation signal to form a first mixed signal, and feeding back the first mixed signal to the controller; the second light receiving device is electrically connected with the controller and is used for receiving the local oscillation signal, converting the optical signal received from the second optical fiber loop into a second electric signal, mixing the second electric signal with the local oscillation signal to form a second mixed signal, and feeding back the second mixed signal to the controller; the controller is further configured to calculate an optical path difference based on the first mixing signal and the second mixing signal and obtain a rotational angular velocity.

The optical fiber gyroscope provided by the embodiment of the application outputs the radio frequency modulation signal and the local oscillation signal through the controller, the light emitting device emits the light signal according to the modulation signal generated based on the radio frequency modulation signal, the first optical fiber ring transmits the light signal emitted by the light emitting device to the first light receiving device, the first light receiving device converts the light signal received from the first optical fiber ring into the first electric signal, the first electric signal and the local oscillation signal are subjected to mixing processing to form a first mixed signal, the first mixed signal is fed back to the controller, the second optical fiber ring transmits the light signal emitted by the light emitting device to the second light receiving device, the second light receiving device converts the light signal received from the second optical fiber ring into the second electric signal, the second electric signal and the local oscillation signal are subjected to mixing processing to form a second mixed signal, the second mixed signal is fed back to the controller, the controller calculates the optical path difference through the first mixed signal and the second mixed signal, and the optical path difference is obtained.

Optionally, the controller includes a control element and a phase-locked loop, where the control element is electrically connected to the first light receiving device and the second light receiving device and is configured to receive the first mixing signal and the second mixing signal, and the control element is electrically connected to the phase-locked loop and is configured to control the phase-locked loop to generate the radio frequency modulation signal and the local oscillation signal.

Optionally, the optical fiber gyroscope further comprises a modulation control circuit, wherein the modulation control circuit is connected between the controller and the light emitting device, and the modulation control circuit generates the modulation signal based on the radio frequency modulation signal and controls the light emitting device to emit light through the modulation signal.

Optionally, the optical fiber gyroscope further includes a local oscillation processing circuit, the local oscillation processing circuit is connected between the controller and the first light receiving device and between the controller and the second light receiving device, and the local oscillation processing circuit is configured to process the local oscillation signal.

Optionally, the first light receiving device includes a first photoelectric conversion element and a first mixing element connected to the first photoelectric conversion element, where the first photoelectric conversion element is optically coupled to the first optical fiber ring, and is configured to convert the optical signal transmitted through the first optical fiber ring into the first electrical signal, and transmit the first electrical signal to the first mixing element, and the first mixing element is further configured to receive the local oscillation signal, and mix the local oscillation signal with the first electrical signal to generate the first mixing signal.

Optionally, the second light receiving device includes a second photoelectric conversion element and a second mixing element connected to the second photoelectric conversion element, where the second photoelectric conversion element is optically coupled to the second optical fiber ring, and is configured to convert the optical signal transmitted through the second optical fiber ring into the second electrical signal, and transmit the second electrical signal to the second mixing element, and the second mixing element is further configured to receive the local oscillation signal, and mix the local oscillation signal with the second electrical signal to generate the second mixing signal.

Optionally, the optical fiber gyroscope further includes a first filter amplifying circuit and a second filter amplifying circuit, where the first filter amplifying circuit is connected between the first light receiving device and the controller and is used for processing the first mixed signal, and the second filter amplifying circuit is connected between the second light receiving device and the controller and is used for processing the second mixed signal.

Optionally, the optical fiber gyroscope further includes a first bias circuit connected between the controller and the first light receiving device and a second bias circuit connected between the controller and the second light receiving device, the first bias circuit being used for adjusting a bias voltage of the first light receiving device, the second bias circuit being used for adjusting a bias voltage of the second light receiving device.

Optionally, the optical fiber gyroscope further includes a first temperature sensor and a second temperature sensor connected to the controller, where the first temperature sensor is disposed near the first light receiving device and is used for collecting the temperature of the first light receiving device, the second temperature sensor is disposed near the second light receiving device and is used for collecting the temperature of the second light receiving device, and the controller controls the first bias circuit to adjust the bias voltage of the first light receiving device based on the temperature collected by the first temperature sensor, and controls the second bias circuit to adjust the bias voltage of the second light receiving device based on the temperature collected by the second temperature sensor.

Optionally, the optical fiber gyroscope further includes a data output interface electrically connected with the controller, and is used for outputting the rotation angular velocity.

Optionally, the optical fiber gyroscope further includes a light splitting element, where the light splitting element is disposed between the light emitting device and the optical fiber ring, and is configured to split an optical signal emitted by the light emitting device into two optical signals, where the two optical signals are transmitted to the first light receiving device through the first optical fiber ring and to the second light receiving device through the second optical fiber ring respectively.

Optionally, the light emitting device includes a first light emitting device for emitting a first light signal according to a first modulation signal generated based on the radio frequency modulation signal, the first light signal is transmitted to the first light receiving device through the first optical fiber ring, and a second light emitting device for emitting a second light signal according to a second modulation signal generated based on the radio frequency modulation signal, and the second light signal is transmitted to the second light receiving device through the second optical fiber ring.

The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description and drawings, and from the claims.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of an optical fiber gyroscope according to an embodiment of the present application.

Fig. 2 is a schematic diagram of a modulation control circuit according to an embodiment of the application.

Fig. 3 is a schematic structural diagram of a local oscillation processing circuit according to an embodiment of the present application.

Fig. 4 is a schematic structural diagram of a local oscillation processing circuit according to another embodiment of the present application.

Fig. 5 is a schematic diagram of a filter amplifying circuit according to an embodiment of the application.

Fig. 6 is a schematic diagram of a bias circuit according to an embodiment of the application.

Fig. 7 is a schematic structural diagram of an optical fiber gyroscope according to another embodiment of the present application.

Reference numerals: the fiber optic gyroscopes 100, 200; the controllers 11, 21; the light emitting devices 13, 23; a spectroscopic element 151; the first fiber loop 152, 251; a second fiber optic ring 153, 252; the first light receiving devices 171, 271; a second light receiving device 172, 272; data output interfaces 19, 29; control elements 111, 211; a phase-locked loop circuit 112, 212; the first photoelectric conversion elements 1711, 2711; the first mixing elements 1712, 2712; a modulation control circuit 12; local oscillation processing circuits 14, 24; second photoelectric conversion elements 1721, 2721; second mixing elements 1722, 2722; a first filter amplification circuit 181, 281; a second filter amplifier circuit 182, 282; first bias circuits 161, 261; a second bias circuit 163, 263; the first temperature sensor 162, 262; second temperature sensors 164, 264; a first light emitting device 231, a second light emitting device 233; a first modulation control circuit 221; a second modulation control circuit 222.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

Referring to fig. 1, an optical fiber gyroscope 100 according to an embodiment of the present application includes a controller 11, a light emitting device 13, a light splitting element 151, a first optical fiber ring 152, a second optical fiber ring 153, a first light receiving device 171, a second light receiving device 172, and a data output interface 19.

The controller 11 outputs two clock signals. The two paths of clock signals are radio frequency modulation signals and local oscillation signals respectively. In this embodiment, the radio frequency modulated signal and the local oscillation signal are both high frequency signals, and have phase synchronization and frequency difference.

The controller 11 is electrically connected with the light emitting device 13 and is used for controlling the light emitting device 13 to emit light; electrically connected to the first light receiving device 171 and the second light receiving device 172, respectively, for transmitting local oscillation signals to the first light receiving device 171 and the second light receiving device 172, receiving the first mixing signals and the second mixing signals fed back from the first light receiving device 171 and the second light receiving device 172, and calculating a rotation angular velocity of the optical fiber gyroscope 100 based on the first mixing signals and the second mixing signals; and is electrically connected to the data output interface 19, and is configured to output the calculated rotational angular velocity through the data output interface 19.

In this embodiment, the controller 11 includes a control element 111 and a pll circuit 112 electrically connected to the control element 111.

The control element 111 is electrically connected to the first light receiving device 171 and the second light receiving device 172, and is configured to receive the first mixing signal and the second mixing signal fed back by the first light receiving device 171 and the second light receiving device 172, and calculate a rotation angular velocity of the optical fiber gyroscope 100 based on the first mixing signal and the second mixing signal; is connected to a data output interface 19 for outputting the calculated rotational angular velocity via the data output interface 19. The control element 111 may be a field programmable gate array (Feild Programmable GATE ARRAY, FPGA), a digital signal Processor (DIGITAL SIGNAL Processor, DSP), a complex programmable logic device (Complex Programmable Logic Device, CPLD), a micro-control unit (Microcontroller Unit, MCU), or the like.

The pll circuit 112 generates the two clock signals. The phase-locked loop circuit 112 is electrically connected to the light emitting device 13, and is configured to output a radio frequency modulation signal to control the light emitting device 13 to emit light; is electrically connected to the first light receiving device 171 and the second light receiving device 172, and is used for transmitting local oscillation signals to the first light receiving device 171 and the second light receiving device 172. The phase-locked loop circuit 112 may be a phase-locked loop (Phase Locked Loop, PLL), a direct digital frequency Synthesizer (DIRECT DIGITAL Synthesizer, DDS), CPLD, FPGA, or the like. It will be appreciated that the specific configuration of the pll circuit 112 is not limited, so long as it is capable of generating the two clock signals.

It will be appreciated that in other embodiments, the control element 111 can implement a phase-locked loop function, and the phase-locked loop circuit 112 can be omitted, and the control element 111 can be an FPGA, a CPLD, or an MCU with a phase-locked loop function. The application does not limit the specific type and structure of the MCU with the phase-locked loop function, as long as the MCU can realize the phase-locked loop function.

It will be appreciated that in this embodiment, the fiber optic gyroscope 100 also includes a modulation control circuit 12. The modulation control circuit 12 is connected between the controller 11 and the light emitting device 13 for generating a modulation signal based on the radio frequency modulation signal to control the light emitting device 13 to emit light. In this embodiment, the modulation control circuit 12 is connected between the pll circuit 112 and the light emitting device 13, and is electrically connected to the control element 111. The modulation control circuit 12 is controlled by the control element 111, generates a modulation signal based on the radio frequency modulation signal transmitted by the phase-locked loop circuit 112, and further controls the light emitting device 13 to emit light by the modulation signal. Referring to fig. 2, a modulation control circuit 12 drives a light emitting device 13 (a laser diode in the drawing) through a triode. Specifically, in this embodiment, the modulation control circuit 12 controls the on/off of the power supply circuit of the light emitting device 13 by controlling the on/off of the transistor, thereby controlling the light emission of the light emitting device 13. The base electrode of the triode is connected with a power supply. In this embodiment, the base of the triode is connected to the power supply through a parallel structure (e.g., the parallel structure of the capacitor C49 and the resistor R71 in fig. 2) and a resistor (e.g., the resistor R77 in fig. 2) connected in series with the parallel structure. The rf modulated signal input is connected to the parallel structure (e.g., between capacitor C49 and resistor R71 of the parallel structure shown in fig. 2). The rf modulated signal input is coupled to the rf modulated signal output of the phase locked loop circuit 112. The collector of the triode is connected to a light emitting device, such as the series laser diode LD2 in fig. 2. Optionally, the collector of the triode is connected to the cathode of the light emitting device through resistor R80. In this embodiment, the collector of the triode is further connected to the power supply through a parallel structure (for example, a parallel structure of the capacitor 81 and the resistor R72 shown in fig. 2) and a resistor (for example, the resistor R70 shown in fig. 2) connected in series with the parallel structure. The emitter of the triode is grounded. The anode of the light emitting device 13 is connected to a power source. Alternatively, the light emitting device 13 is connected to the power supply through a resistor (e.g., resistor R19 shown in the convex). The power supply and the access point of the light emitting device 13 are for example located between the series connected laser diodes as shown in fig. 2. In this embodiment, the light emitting device 13 is further grounded through a resistor (e.g., resistor R81 shown in fig. 2). The modulation control circuit 12 includes a pull-down signal input PD. As shown in fig. 2, the pull-down signal input terminal is located between the light emitting device 13 and the resistor R81.

It will be appreciated that only the configuration of the modulation control circuit 12 is illustrated in this embodiment. In other embodiments, the modulation control circuit 12 may have other structures, as long as the modulation control circuit 12 can generate a modulation signal based on the radio frequency modulation signal to control the light emitting device 13 to emit light.

The light emitting device 13 is electrically connected to the controller 11 for emitting an optical signal based on the modulated signal. The light emitting device 13 may be a Laser Diode (LD), a light emitting Diode (LIGHT EMITTING Diode, LED), or the like.

The light splitting element 151 is disposed between the light emitting device 13 and the first optical fiber ring 152 and the second optical fiber ring 153, and is used for splitting the optical signal emitted by the light emitting device 13 into two paths of optical signals. One of the two optical signals enters the first optical fiber ring 152, is transmitted to the first light receiving device 171 through the first optical fiber ring 152, and the other of the two optical signals enters the second optical fiber ring 153, and is transmitted to the second light receiving device 172 through the second optical fiber ring 153. In this embodiment, the spectroscopic element 151 is a half mirror.

It will be appreciated that in other embodiments, a focusing lens or an optical element with a conical reflecting surface is disposed between the optical splitter 151 and the first optical fiber ring 152, so as to couple one of the two optical signals formed by the optical splitter 151 into the first optical fiber ring 152. Similarly, a focusing lens or an optical element having a conical reflecting surface may be provided between the spectroscopic element 151 and the second optical fiber ring 153. The first optical fiber ring 152 is disposed between the light splitting element 151 and the first light receiving device 171, and both ends of the first optical fiber ring 152 are optically coupled with the light splitting element 151 and the first light receiving device 272, respectively. The optical splitting element 151 splits the optical signal emitted from the light emitting device 13 into two optical signals, and one of the optical signals is transmitted to the first light receiving device 171 through the first optical fiber ring 152.

The second optical fiber ring 153 is disposed between the light splitting element 151 and the second light receiving device 172, and both ends of the second optical fiber ring 153 are optically coupled with the light splitting element 151 and the second light receiving device 172, respectively. The optical splitter 151 splits the optical signal emitted from the light emitting device 13 into two optical signals, and then the other optical signal is transmitted to the second light receiving device 172 through the second optical fiber ring 153.

It is understood that a focusing lens or an optical element having a conical reflecting surface may be provided between the first optical fiber ring 152 and the first light receiving device 171 and between the second optical fiber ring 153 and the second light receiving device 172.

The optical fiber of one of the first optical fiber ring 152 and the second optical fiber ring 153 is wound in a clockwise direction, and the optical fiber of the other is wound in a counterclockwise direction. The first optical fiber ring 152 and the second optical fiber ring 153 have the same radius and winding number. In this embodiment, the first optical fiber ring 152 and the second optical fiber ring 153 are wound on the same winding carrier or around the same axis.

The first light receiving device 171 is configured to convert an optical signal transmitted through the first optical fiber loop 152 into a first electrical signal, and to mix the first electrical signal with a local oscillation signal to form a first mixed signal, and to feed back the first mixed signal to the controller 11.

In this embodiment, the first light receiving device 171 includes a first photoelectric conversion element 1711 and a first mixing element 1712 electrically connected to the first photoelectric conversion element 1711.

The first photoelectric conversion element 1711 is optically coupled to the first optical fiber ring 152, and is configured to receive an optical signal transmitted through the first optical fiber ring 152, convert the optical signal into a first electrical signal, and transmit the first electrical signal to the first mixing element 1712. The first photoelectric conversion element 1711 may be an avalanche photodiode (AVALANCHE PHOTO DIODE, APD), a photodiode (Photo Diode), a Positive INTRINSIC NEGATIVE (PTN) photodiode, or a photoelectric conversion device such as a photomultiplier.

The first mixing element 1712 is further electrically connected to the controller 11, and is configured to receive the local oscillation signal output by the controller 11. In this embodiment, the first mixing element 1712 is electrically connected to the pll circuit 112 to receive the local oscillation signal generated by the pll circuit 112. The first mixing element 1712 mixes the local oscillation signal with the first electric signal received from the first photoelectric conversion element 1711 to form a first mixed signal, and feeds back the first mixed signal to the controller 11. In this embodiment, the first mixing element 1712 is electrically connected to the control element 111. The first mixing element 1712 feeds back the first mixing signal to the control element 111.

It is to be understood that, in the present embodiment, the specific configuration of the first mixing element 1712 is not limited as long as it can perform mixing processing on the local oscillation signal and the electric signal received from the first photoelectric conversion element 1711, and generate a first mixing signal and feed back the first mixing signal to the controller 11.

It is understood that in other embodiments, the first mixing element 1712 may be omitted, and the first electrical signal and the local oscillation signal are mixed by the first photoelectric conversion element 1711.

The second light receiving device 172 is configured to convert the optical signal transmitted through the second optical fiber ring 153 into a second electrical signal, and perform mixing processing on the second electrical signal and the local oscillation signal to form a second mixed signal, and feed back the second mixed signal to the controller 11.

In this embodiment, the second light receiving device 172 includes a second photoelectric conversion element 1721 and a second mixing element 1722 electrically connected to the second photoelectric conversion element 1721.

The second photoelectric conversion element 1721 is optically coupled to the second optical fiber ring 153, and is configured to receive the optical signal transmitted through the second optical fiber ring 153, convert the optical signal into a second electrical signal, and transmit the second electrical signal to the second mixing element 1722. The second photoelectric conversion element 1721 may be an avalanche photodiode (AVALANCHE PHOTO DIODE, APD), a photodiode (Photo Diode), a Positive INTRINSIC NEGATIVE (PIN) photodiode, or a photoelectric conversion device such as a photomultiplier.

The second mixing element 1722 is further electrically connected to the controller 11, and is configured to receive the local oscillation signal output by the controller 11. In this embodiment, the second mixing element 1722 is electrically connected to the pll circuit 112 to receive the local oscillation signal generated by the pll circuit 112. The second mixing element 1722 mixes the local oscillation signal with the electric signal received from the second photoelectric conversion element 1721 to form a second mixing signal, and feeds back the second mixing signal to the controller 11. In this embodiment, the second mixing element 1722 is electrically connected to the control element 111, and the second mixing element 1722 feeds back the second mixing signal to the control element 111.

It is to be understood that, in the present embodiment, the specific structure of the second mixing element 1722 is not limited as long as it can perform mixing processing on the local oscillation signal and the electric signal received from the second photoelectric conversion element 1721, and generate a second mixing signal and feed back to the controller 11.

It is understood that in other embodiments, the second mixing element 1722 may be omitted, and the second electrical signal and the local oscillation signal are mixed by the second photoelectric conversion element 1721.

It will be appreciated that in this embodiment, the optical fiber gyroscope 100 further includes a local oscillator processing circuit 14. The local oscillation processing circuit 14 is connected between the controller 11 and the first light receiving device 171 and the second light receiving device 172, and is configured to perform processing such as filtering and amplifying on the local oscillation signal. Further, the local oscillation processing circuit 14 is connected between the phase-locked loop circuit 112 and the first light receiving device 171 and the second light receiving device 172. In this embodiment, the local oscillation processing circuit 14 is connected between the pll circuit 112 and the first mixing element 1712 and the second mixing element 1722, and is configured to process the local oscillation signal output by the pll circuit 112 and send the processed local oscillation signal to the first mixing element 1712 and the second mixing element 1722. Referring to fig. 3, in the present embodiment, the local oscillation processing circuit 14 includes a MOS transistor. The gate 1 of the MOS tube is connected with the local oscillation signal output end of the phase-locked loop circuit 112. Optionally, the gate 1 of the MOS transistor is connected to the local oscillation signal output end of the pll circuit 112 through a parallel connection structure (for example, a parallel connection structure of a capacitor and a resistor in fig. 3). The drain electrode 2 of the MOS tube is grounded. Optionally, the drain electrode 2 of the MOS transistor is grounded via a parallel connection structure (e.g., a parallel connection structure of a capacitor and a resistor in fig. 3). The source 3 of the MOS transistor is connected to a power source VCC, a first light receiving device 171, and a second light receiving device 172, respectively. Alternatively, the source 3 of the MOS transistor is connected to the power source VCC through a parallel structure (for example, a parallel structure of an inductor and a resistor in fig. 3), and is connected to the first light receiving device 171 and the second light receiving device 172 through a capacitor connected in series with the parallel structure. It should be understood that the local oscillation processing circuit shown in fig. 3 is only an example, and is not limited thereto.

Referring to fig. 4, in another embodiment, the local oscillation processing circuit 14 includes a MOS transistor. The gate 1 of the MOS tube is connected with the local oscillation signal output end of the phase-locked loop circuit 112. Optionally, the gate 1 of the MOS transistor is connected to the local oscillator signal output end of the pll circuit 112 through a parallel connection structure (for example, a parallel connection structure of a resistor and a capacitor in fig. 4). The drain electrode 2 of the MOS tube is connected with a power supply VCC. The source 3 of the MOS transistor is grounded via a parallel structure (e.g., a parallel structure of an inductor and a resistor in fig. 4), and is connected to the first light receiving device 171 and the second light receiving device 172 via a capacitor connected in series with the parallel structure. It should be understood that the local oscillation processing circuit 14 shown in fig. 4 is only an example, and is not limited thereto.

It can be understood that, in the present embodiment, the optical fiber gyroscope 100 further includes a first filter amplifying circuit 181 and a second filter amplifying circuit 182. The first filter amplification circuit 181 is connected between the first light receiving device 171 and the controller 11, and is configured to amplify, filter, and the like the first mixed signal output from the first light receiving device 171. The second filter amplification circuit 182 is connected between the second light receiving device 172 and the controller 11, and is used for amplifying, filtering, and the like the second mixed signal output from the second light receiving device 172. In this embodiment, the first filter amplifying circuit 181 and the second filter amplifying circuit 182 are respectively configured to cancel the sum frequency signals in the first mixing signal and the second mixing signal to obtain a first difference frequency signal and a second difference frequency signal, and amplify the first difference frequency signal and the second difference frequency signal and feed back the amplified first difference frequency signal and the second difference frequency signal to the controller 11. In the present embodiment, the first filter amplifier circuit 181 is connected between the first mixing element 1712 and the control element 111, and the second filter amplifier circuit 182 is connected between the second mixing element 1722 and the control element 111. In this embodiment, the first filter amplifier circuit 181 and the second filter amplifier circuit 182 are low-pass filter amplifiers for filtering the sum frequency signal in the mixed signal and reserving the difference frequency signal. The first filter amplifier circuit 181 and the second filter amplifier circuit 182 have the same configuration, and in this embodiment, the configuration of the filter amplifier circuit is described taking the first filter amplifier circuit 181 as an example. Referring to fig. 5, the first filter amplifying circuit 181 includes a filter amplifier. The non-inverting input 3 of the filter amplifier is connected to a power supply. Optionally, the non-inverting input of the filter amplifier is connected to the power supply sequentially through a parallel structure (e.g., a parallel structure of the resistor R36 and the capacitor C26 in fig. 5) and a resistor (e.g., the resistor R34 in fig. 5) connected in series with the parallel structure. The inverting input 2 of the filter amplifier is connected to the input of the first mixing signal. The input terminal of the first mixing signal is connected to the signal output terminal of the first light receiving device 171 (in this embodiment, the signal output terminal of the first mixing element 1712), and optionally, the inverting input terminal 2 of the filter amplifier is connected to the input terminal of the first mixing signal sequentially through a resistor (e.g., the resistor R32 in fig. 5) and a capacitor (e.g., the capacitor C23 in fig. 5). The signal output end 1 of the filter amplifier is connected with the signal output end of the first filter amplifying circuit. Optionally, the signal output terminal 1 of the filter amplifier is connected to the signal output terminal of the first filter amplifier circuit through a capacitor (e.g. capacitor C24 in fig. 5). The signal output terminal of the first filter amplifier circuit is connected to the controller 11 (in this embodiment, the control element 111). Optionally, the inverting input 2 of the filter amplifier is connected to the signal output 1 of the filter amplifier. Alternatively, the inverting input 2 of the filter amplifier is connected to the signal output 1 of the filter amplifier through a parallel arrangement (e.g., a parallel arrangement of a capacitor C27 and a resistor R30 in fig. 5).

The connection relationship between the second filter amplifier circuit 182 and the controller 11 (the control element 111 in the present embodiment) and the second light receiving device 172 (the second mixing element 1722 in the present embodiment) are similar to the connection relationship between the first filter amplifier circuit 181 and the controller 11 (the control element 111 in the present embodiment) and the first light receiving device 171 (the first mixing element 1712 in the present embodiment), and will not be described again.

It can be understood that in the present embodiment, the optical fiber gyroscope 100 further includes a first bias circuit 161 and a second bias circuit 163. The first bias circuit 161 is connected between the controller 11 and the first light receiving device 171 for adjusting a bias voltage of the first light receiving device 171. In the present embodiment, the first bias circuit 161 is connected between the control element 111 and the first photoelectric conversion element 1711. The second bias circuit 163 is connected between the controller 11 and the second light receiving device 172 for adjusting the bias voltage of the second light receiving device 172. In the present embodiment, the second bias circuit 163 is connected between the control element 111 and the second photoelectric conversion element 1721. The first bias circuit 161 and the second bias circuit 163 have the same configuration, and in this embodiment, the configuration of the bias circuit is described by taking the first bias circuit 161 as an example. Referring to fig. 6, the first bias circuit 161 has a signal input terminal connected to the control element 111 for receiving a control signal, a signal output terminal connected to the control element 111 for providing a sampling signal to the control element 111, and a bias voltage output terminal connected to the first light receiving device 171. The signal input end is connected with the base electrode of a triode. The collector of the triode is grounded. The emitter of the triode is connected with a power supply VCC through an inductor L1 respectively, and is connected with a paranoid voltage output end through a diode, a resistor R1 and a resistor R2 in sequence. A capacitor C1 is connected between the diode and the resistor R1, and the capacitor C1 is connected in parallel with the resistor R1 and grounded. A grounded parallel structure is connected between the resistor R1 and the resistor R2. The parallel structure comprises a capacitor C2 and a series structure connected with the capacitor C2 in parallel. The series structure comprises a resistor R3 and a resistor R4 which are connected in series. The signal output end of the sampling signal is connected between the resistors R3 and R4. The control element 111 samples the bias voltage of the first light receiving device 171 and inputs a control signal via the signal input terminal of the first bias circuit 161 according to the sampled bias voltage to adjust the bias voltage of the first light receiving device 171. In this embodiment, the control element 111 inputs a pulse width modulation signal via the signal input terminal of the first bias circuit 161 according to the sampled bias voltage, and adjusts the bias voltage of the first light receiving device 171 by adjusting the duty ratio of the pulse width modulation signal.

The connection relationship between the second bias circuit 163 and the control element 111 and the second light receiving device 172 are similar to the connection relationship between the first bias circuit 161 and the control element 111 and the first light receiving device 171, and will not be described here again.

It is understood that in other embodiments, the fiber optic gyroscope 100 may further include a first temperature sensor 162 and a second temperature sensor 164. The first temperature sensor 162 is electrically connected to the controller 11 and disposed near the first light receiving device 171, for collecting the temperature of the first light receiving device 171. The controller 11 controls the first bias circuit 161 to adjust the bias voltage of the first light receiving device 171 based on the temperature acquired by the first temperature sensor 162. In this embodiment, the first temperature sensor 162 is electrically connected to the control element 111. The control element 111 controls the first bias circuit 161 to adjust the bias voltage of the first photoelectric conversion element 1711 based on the temperature acquired by the first temperature sensor 162.

The second temperature sensor 164 is electrically connected to the controller 11 and disposed near the second light receiving device 172, for collecting the temperature of the second light receiving device 172. The controller 11 controls the second bias circuit 163 to adjust the bias voltage of the second light receiving device 172 based on the temperature acquired by the second temperature sensor 164. In this embodiment, the second temperature sensor 164 is electrically connected to the control element 111. The control element 111 controls the second bias circuit 163 to adjust the bias voltage of the second photoelectric conversion element 1721 based on the temperature acquired by the second temperature sensor 164.

The data output interface 19 is electrically connected to the controller 11, and is used for outputting the rotational angular velocity calculated by the controller 11. The data output interface 19 may be a serial interface, a serial external interface (SERIAL PERIPHERAL INTERFACE, SPI) or a controller area network (Controller Area Network, CAN) interface.

The optical fiber gyroscope provided by the embodiment outputs the radio frequency modulation signal and the local oscillation signal through the controller, the light emitting device emits the optical signal according to the modulation signal generated based on the radio frequency modulation signal, the first optical fiber ring is optically coupled with the light splitting element and the first light receiving device respectively, the first light receiving device converts the optical signal received from the first optical fiber ring into the electric signal, and carries out frequency mixing processing on the electric signal and the local oscillation signal to form a first frequency mixing signal, and the first frequency mixing signal is fed back to the controller, the second optical fiber ring is optically coupled with the light splitting element and the second light receiving device respectively, the second light receiving device converts the optical signal received from the second optical fiber ring into the electric signal, carries out frequency mixing processing on the electric signal and the local oscillation signal to form a second frequency mixing signal, and feeds back the second frequency mixing signal to the controller, and the controller calculates an optical path difference through the first frequency mixing signal and the second frequency mixing signal to obtain a rotation angle speed.

Further, in this embodiment, the optical signals emitted by the light emitting devices are respectively transmitted to the first light receiving device and the second light receiving device through the first optical fiber ring and the second optical fiber ring, then the first light receiving device and the second light receiving device respectively convert the optical signals into electrical signals, and mix the electrical signals with the local oscillation signals to form first mixed signals and second mixed signals, the controller calculates the optical path difference according to the first mixed signals and the second mixed signals, and further obtains the rotation angular velocity.

Referring to fig. 7, an optical fiber gyroscope 200 according to another embodiment of the present application includes a controller 21, a first light emitting device 231, a second light emitting device 233, a first optical fiber ring 251, a second optical fiber ring 253, a first light receiving device 271, a second light receiving device 272, and a data output interface 29.

The controller 21 outputs two clock signals. The two paths of clock signals are radio frequency modulation signals and local oscillation signals respectively. In this embodiment, the radio frequency modulated signal and the local oscillation signal are both high frequency signals, and have phase synchronization and frequency difference.

The controller 21 is electrically connected to the first light emitting device 231 and the second light emitting device 233, and is configured to control the first light emitting device 231 and the second light emitting device 233 to emit light; electrically connected to the first light receiving device 271 and the second light receiving device 272, respectively, for transmitting local oscillation signals to the first light receiving device 271 and the second light receiving device 272, and receiving the first mixing signals and the second mixing signals fed back from the first light receiving device 271 and the second light receiving device 272, and calculating a rotation angular velocity of the optical fiber gyroscope 200 based on the first mixing signals and the second mixing signals; and is electrically connected to the data output interface 29, and is configured to output the calculated rotational angular velocity through the data output interface 29.

In this embodiment, the controller 21 includes a control element 211 and a pll circuit 212 electrically connected to the control element 211.

The control element 211 is electrically connected to the first light receiving device 271 and the second light receiving device 272, and is configured to receive the first mixing signal and the second mixing signal fed back by the first light receiving device 271 and the second light receiving device 272, and calculate a rotation angular velocity of the optical fiber gyroscope 200 based on the first mixing signal and the second mixing signal; is connected to the data output interface 29, and outputs the calculated rotational angular velocity through the data output interface 29. The control element 211 may be a field programmable gate array (Feild Programmable GATE ARRAY, FPGA), a digital signal Processor (DIGITAL SIGNAL Processor, DSP), a complex programmable logic device (Complex Programmable Logic Device, CPLD), a micro-control unit (Microcontroller Unit, MCU), or the like.

The pll circuit 212 generates the two clock signals. The pll circuit 212 is electrically connected to the first light emitting device 231 and the second light emitting device 233, and is configured to output a radio frequency modulation signal to control the first light emitting device 231 and the second light emitting device 233 to emit light; is electrically connected to the first light receiving device 271 and the second light receiving device 272, and is used for transmitting local oscillation signals to the first light receiving device 271 and the second light receiving device 272. The phase-locked loop circuit 212 may be a phase-locked loop (Phase Locked Loop, PLL), a direct digital frequency Synthesizer (DIRECT DIGITAL Synthesizer, DDS), CPLD, FPGA, or the like.

It should be understood that, in the present embodiment, the specific structure of the pll circuit 212 is not limited, as long as it can generate the two clock signals.

It is understood that in other embodiments, the control element 211 can implement a phase-locked loop function, and the phase-locked loop circuit 212 can be omitted. The control element 211 may be an FPGA, a CPLD, and an MCU with a phase-locked loop function. The application does not limit the specific type and structure of the MCU with the phase-locked loop function, as long as the MCU can realize the phase-locked loop function.

It can be understood that in the present embodiment, the optical fiber gyroscope 200 further includes a first modulation control circuit 221 and a second modulation control circuit 222. The first modulation control circuit 221 is connected between the controller 21 and the first light emitting device 231, and is configured to generate a first modulation signal based on the radio frequency modulation signal to control the first light emitting device 231 to emit light. In this embodiment, the first modulation control circuit 221 is connected between the pll circuit 212 and the first light emitting device 231, and is electrically connected to the control element 211. The first modulation control circuit 221 is controlled by the control element 211, generates a first modulation signal based on the radio frequency modulation signal sent by the phase-locked loop circuit 212, and further controls the first light emitting device 231 to emit light through the first modulation signal.

The second modulation control circuit 222 is connected between the controller 21 and the second light emitting device 233, and is configured to generate a second modulation signal based on the radio frequency modulation signal, so as to control the second light emitting device 233 to emit light. In this embodiment, the second modulation control circuit 222 is connected between the pll circuit 212 and the second light emitting device 233, and is electrically connected to the control element 211. The second modulation control circuit 222 is controlled by the control element 211, generates a second modulation signal based on the radio frequency modulation signal sent by the phase-locked loop circuit 212, and further controls the second light emitting device 233 to emit light through the first modulation signal.

In this embodiment, the specific structure of the first modulation control circuit 221 and the connection relationship between the first modulation control circuit and the controller 21 and the first light emitting device 231, and the specific structure of the second modulation control circuit 222 and the connection relationship between the second modulation control circuit and the controller 21 and the second light emitting device 233 are similar to the specific structure of the modulation control circuit 12 and the connection relationship between the modulation control circuit and the controller 11 and the light emitting device 13 in the foregoing embodiment, and are not repeated here.

The first light emitting device 231 and the second light emitting device 233 are electrically connected to the controller 21, and are configured to emit a first light signal and a second light signal based on the first modulation signal and the second modulation signal, respectively. The first light emitting device 231 and the second light emitting device 233 may be a Laser Diode (LD), a light emitting Diode (LIGHT EMITTING Diode, LED), or the like.

The first optical fiber ring 251 is disposed between the first light emitting device 231 and the first light receiving device 271, and both ends of the first optical fiber ring 251 are optically coupled with the first light emitting device 231 and the first light receiving device 271, respectively, for transmitting the first optical signal emitted from the first light emitting device 231 to the first light receiving device 271. In this embodiment, both ends of the first optical fiber ring 251 are aligned with the light emitting end of the first light emitting device 231 and the light receiving end of the first light receiving device 271, respectively, so that both ends of the first optical fiber ring 251 are optically coupled with the first light emitting device 231 and the first light receiving device 271, respectively.

It can be appreciated that in other embodiments, a focusing lens is disposed between the light emitting end of the first light emitting device 231 and the light entering end of the first optical fiber ring 251, and the light is coupled into the first optical fiber ring 251 through the focusing lens after exiting from the light emitting end of the first light emitting device 231. Optionally, a focusing lens is also disposed between the first optical fiber ring 251 and the first light receiving device 271, and the light transmitted by the first optical fiber ring 251 exits from the first optical fiber ring 251 and is coupled into the first light receiving device 271 through the focusing lens.

It will be appreciated that in other embodiments, an optical element having a conical reflecting surface is disposed between the first light emitting device 231 and the first optical fiber ring 251, and the light emitted by the first light emitting device 231 is converged into the first optical fiber ring 251 by the optical element. In this embodiment, the optical element is substantially in a cone shape and includes a light incident end and a light emergent end opposite to the light incident end. The aperture of the light-in end is larger than that of the light-out end. The inner cylinder wall of the optical element is a reflecting surface. The light-in end of the optical element is aligned with the light-out end of the first light emitting device 231, and the light-out end of the optical element is aligned with the incident end of the first optical fiber ring 251, so as to collect the light emitted by the first light emitting device 231 into the first optical fiber ring 251. Alternatively, an optical device having a conical reflecting surface may be provided between the first optical fiber ring 251 and the first light receiving device 271. At this time, the light incident end of the optical element is aligned with the light emitting end of the first optical fiber ring 251, and the light emitting end of the optical element is aligned with the first light receiving device 271, so as to achieve that the light transmitted through the first optical fiber ring 251 is converged into the first light receiving device 271 through the optical element.

The second optical fiber ring 253 is disposed between the second light emitting device 233 and the second light receiving device 272, and both ends of the second optical fiber ring 253 are optically coupled with the second light emitting device 233 and the second light receiving device 272, respectively, for transmitting the second optical signal emitted from the second light emitting device 233 to the second light receiving device 272. In this embodiment, two ends of the second optical fiber ring 253 are aligned with the light emitting end of the second light emitting device 233 and the light receiving end of the second light receiving device 272, respectively, so that two ends of the second optical fiber ring 253 are optically coupled with the second light emitting device 233 and the second light receiving device 272, respectively.

It can be appreciated that in other embodiments, a focusing lens is disposed between the light emitting end of the second light emitting device 233 and the light entering end of the second optical fiber ring 253, and the light is coupled into the second optical fiber ring 253 through the focusing lens after exiting from the light emitting end of the second light emitting device 233. Optionally, a focusing lens is also disposed between the second optical fiber ring 253 and the second light receiving device 272, and the light transmitted by the second optical fiber ring 253 exits from the second optical fiber ring 253 and then is coupled into the second light receiving device 272 through the focusing lens.

It will be appreciated that in other embodiments, an optical element having a conical reflecting surface is disposed between the second light emitting device 233 and the second optical fiber ring 253, and the light emitted by the second light emitting device 233 is converged into the second optical fiber ring 253 by the optical element. The light-in end of the optical element is aligned with the light-out end of the second light emitting device 233, and the light-out end of the optical element is aligned with the light-in end of the second optical fiber ring 253 to concentrate the light emitted by the second light emitting device 233 into the second optical fiber ring 253. Optionally, an optical element having a conical reflecting surface may be disposed between the second optical fiber ring 253 and the second light receiving device 272, and the light transmitted through the second optical fiber ring 253 is converged into the second light receiving device 272 by the optical element. The light incident end of the optical element is aligned with the light emitting end of the second optical fiber ring 253, and the light emitting end of the optical element is aligned with the second light receiving device 272, so that the light transmitted through the second optical fiber ring 253 is converged into the second light receiving device 272 through the optical element.

The optical fiber of one of the first optical fiber ring 251 and the second optical fiber ring 253 is wound in a clockwise direction, and the optical fiber of the other is wound in a counterclockwise direction. The first and second fiber loops 251 and 253 have the same radius and number of windings. In this embodiment, the first optical fiber ring 251 and the second optical fiber ring 253 are wound on the same winding carrier or around the same axis.

The first light receiving device 271 is configured to convert a first optical signal transmitted through the first optical fiber loop 251 into a first electrical signal, and to mix the first electrical signal with a local oscillation signal to form a first mixed signal, and to feed back the first mixed signal to the controller 21.

In this embodiment, the first light receiving device 271 includes a first photoelectric conversion element 2711 and a first mixing element 2712 electrically connected to the first photoelectric conversion element 2711.

The first photoelectric conversion element 2711 is optically coupled to the first optical fiber ring 251 for receiving an optical signal transmitted through the first optical fiber ring 251 and converting the optical signal into a first electrical signal and transmitting the first electrical signal to the first mixing element 2712. The first photoelectric conversion element 2711 may be a photoelectric conversion device such as an avalanche photodiode (AVALANCHE PHOTO DIODE, APD), a photodiode (Photo Diode), a Positive INTRINSIC NEGATIVE (PIN) photodiode, or a photomultiplier.

The first mixing element 2712 is further electrically connected to the controller 21, and is configured to receive a local oscillator signal output by the controller 21. In this embodiment, the first mixing element 2712 is electrically connected to the pll circuit 212 to receive the local oscillation signal generated by the pll circuit 212. The first mixing element 2712 mixes the local oscillation signal with the electric signal received from the first photoelectric conversion element 2711, forms a first mixing signal, and feeds back the first mixing signal to the controller 21. In this embodiment, the first mixing element 2712 feeds back the mixing signal to the control element 211.

It is to be understood that, in the present embodiment, the specific configuration of the first mixing element 2712 is not limited as long as it can perform mixing processing of the local oscillation signal and the electric signal received from the first photoelectric conversion element 2711, generate a first mixing signal, and feed back to the controller 21.

It is understood that in other embodiments, the first mixing element 2712 may be omitted, and the first electrical signal and the local oscillator signal may be mixed by the first photoelectric conversion element 2711.

The second light receiving device 272 is configured to convert the second optical signal transmitted through the second optical fiber loop 253 into a second electrical signal, and mix the second electrical signal with the local oscillation signal to form a second mixed signal, and feed back the second mixed signal to the controller 21.

In this embodiment, the second light receiving device 272 includes a second photoelectric conversion element 2721 and a second mixing element 2722 electrically connected to the second photoelectric conversion element 2721.

The second photoelectric conversion element 2721 is optically coupled to the second optical fiber ring 253, and is configured to receive the second optical signal transmitted through the second optical fiber ring 253, convert the second optical signal into a second electrical signal, and transmit the second electrical signal to the second mixing element 2722. The second photoelectric conversion element 2721 may be an avalanche photodiode (AVALANCHE PHOTO DIODE, APD), a photodiode (Photo Diode), a Positive INTRINSIC NEGATIVE (PIN) photodiode, or a photoelectric conversion device such as a photomultiplier.

The second mixing element 2722 is further electrically connected to the controller 21, and is configured to receive the local oscillation signal output by the controller 21. In this embodiment, the second mixing element 2722 is electrically connected to the pll circuit 212 to receive the local oscillation signal generated by the pll circuit 212. The second mixing element 2722 mixes the local oscillation signal with the electric signal received from the second photoelectric conversion element 2721 to form a second mixed signal, and feeds back the second mixed signal to the controller 21. In this embodiment, the second mixing element 2722 feeds back the second mixing signal to the control element 211.

It is to be understood that, in the present embodiment, the specific structure of the second mixing element 2722 is not limited, as long as it can perform mixing processing on the local oscillation signal and the electric signal received from the second photoelectric conversion element 2721, and generate a second mixing signal and feed back to the controller 21.

It is understood that in other embodiments, the second mixing element 2722 may be omitted, and the second electrical signal and the local oscillation signal are mixed by the second photoelectric conversion element 2721.

It will be appreciated that in this embodiment, the optical fiber gyroscope 200 further includes a local oscillator processing circuit 24. The local oscillation processing circuit 24 is connected between the controller 21 and the first light receiving device 271 and the second light receiving device 272, and is configured to perform processing such as filtering and amplifying on the local oscillation signal. Further, the local oscillation processing circuit 24 is connected between the phase-locked loop circuit 212 and the first light receiving device 271 and the second light receiving device 272. In this embodiment, the local oscillation processing circuit 24 is connected between the phase-locked loop circuit 212 and the first mixing element 2712 and the second mixing element 2722, and is configured to process the local oscillation signal output by the phase-locked loop circuit 212 and send the processed local oscillation signal to the first mixing element 2712 and the second mixing element 2722.

It is understood that the specific structure of the local oscillation processing circuit 24 and the connection relationship between the local oscillation processing circuit 24 and the phase-locked loop circuit 212 and the first mixing element 2712 and the second mixing element 2722 are similar to the specific structure of the local oscillation processing circuit 14 and the connection relationship between the phase-locked loop circuit 112 and the first mixing element 1712 and the second mixing element 1722 in the previous embodiment, and are not repeated here.

It can be understood that in the present embodiment, the optical fiber gyroscope 200 further includes a first filter amplifying circuit 281 and a second filter amplifying circuit 282. The first filter amplification circuit 281 is connected between the first light receiving device 271 and the controller 21, and is configured to amplify, filter, and the like the first mixed signal output from the first light receiving device 271. The second filter amplification circuit 282 is connected between the second light receiving device 272 and the controller 21, and is configured to amplify, filter, and the like the second mixed signal output from the second light receiving device 272. In this embodiment, the first filter amplifying circuit 281 and the second filter amplifying circuit 282 are respectively configured to cancel the sum frequency signals of the first mixing signal and the second mixing signal to obtain a first difference frequency signal and a second difference frequency signal, and amplify the first difference frequency signal and the second difference frequency signal and feed back the amplified first difference frequency signal and the second difference frequency signal to the controller 21. In the present embodiment, the first filter amplifier circuit 281 is connected between the first mixing element 2712 and the control element 211, and the second filter amplifier circuit 282 is connected between the second mixing element 2722 and the control element 211.

It is to be understood that the specific structure of the first filter amplifying circuit 281 and the connection relationship between the first mixing element 2712 and the controller 21, and the specific structure of the second filter amplifying circuit 282 and the connection relationship between the second mixing element 2722 and the controller 21 in the present embodiment are similar to the specific structure of the first filter amplifying circuit 181 and the connection relationship between the first mixing element 1712 and the controller 11, and the specific structure of the second filter amplifying circuit 182 and the connection relationship between the second mixing element 1722 and the controller 11 in the previous embodiment, respectively, and are not repeated herein.

It can be appreciated that in the present embodiment, the fiber optic gyroscope 200 further includes a first bias circuit 261 and a second bias circuit 263. The first bias circuit 261 is connected between the controller 21 and the first light receiving device 271 for adjusting the bias voltage of the first light receiving device 271. In this embodiment, the first bias circuit 261 is connected between the control element 211 and the first photoelectric conversion element 2711. The second bias circuit 263 is connected between the controller 21 and the second light receiving device 272 for adjusting the bias voltage of the second light receiving device 272. In the present embodiment, the second bias circuit 263 is connected between the control element 211 and the second photoelectric conversion element 2721.

It is understood that the specific structure of the first bias circuit 261 and the connection relationship between the first bias circuit 261 and the controller 21 and the first light receiving device 271, and the specific structure of the second bias circuit 263 and the connection relationship between the second bias circuit 21 and the second light receiving device 272 are similar to those of the first bias circuit 161 and the connection relationship between the controller 11 and the first light receiving device 171, and the specific structure of the second bias circuit 163 and the connection relationship between the controller 11 and the second light receiving device 172 in the foregoing embodiments, and will not be repeated herein.

It is understood that in the present embodiment, the optical fiber gyroscope 200 may further include a first temperature sensor 262 and a second temperature sensor 264. The first temperature sensor 262 is electrically connected to the controller 21 and is disposed near the first light receiving device 271 for collecting the temperature of the first light receiving device 271. The controller 21 controls the first bias circuit 261 to adjust the bias voltage of the first light receiving device 271 based on the temperature acquired by the first temperature sensor 262. In this embodiment, the first temperature sensor 262 is electrically connected to the control element 211. The control element 211 controls the first bias circuit 261 to adjust the bias voltage of the first photoelectric conversion element 2711 based on the temperature acquired by the first temperature sensor 262.

The second temperature sensor 264 is electrically connected to the controller 21 and disposed near the second light receiving device 272, for collecting the temperature of the second light receiving device 272. The controller 21 controls the second bias circuit 263 to adjust the bias voltage of the second light receiving device 272 based on the temperature acquired by the second temperature sensor 264. In this embodiment, the second temperature sensor 264 is electrically connected to the control element 211. The control element 211 controls the second bias circuit 263 to adjust the bias voltage of the second photoelectric conversion element 2721 based on the temperature acquired by the second temperature sensor 264.

The data output interface 29 is electrically connected to the controller 21, and is used for outputting the rotational angular velocity calculated by the controller 21. The data output interface 29 may be a serial interface, a serial external interface (SERIAL PERIPHERAL INTERFACE, SPI) or a controller area network (Controller Area Network, CAN) interface.

The optical fiber gyroscope provided by the embodiment outputs the radio frequency modulation signal and the local oscillation signal through the controller, the first light emitting device and the second light emitting device respectively emit the first optical signal and the second optical signal according to the first modulation signal and the second modulation signal generated based on the radio frequency modulation signal, the first optical fiber ring is respectively optically coupled with the first light emitting device and the first light receiving device, the first light receiving device converts the first optical signal received from the first optical fiber ring into the first electric signal, the first electric signal and the local oscillation signal are subjected to frequency mixing processing to form a first frequency mixing signal, the first frequency mixing signal is fed back to the controller, the second optical fiber ring is respectively optically coupled with the second light emitting device and the second light receiving device, the second optical signal received from the second optical fiber ring is converted into the second electric signal, the second electric signal and the local oscillation signal are subjected to frequency mixing processing to form a second frequency mixing signal, and the second frequency mixing signal is fed back to the controller, the controller calculates the optical path difference through the first frequency mixing signal and the second frequency mixing signal, and further the rotation angle speed is obtained.

Further, in this embodiment, the first light emitting device and the second light emitting device emit light signals according to modulation signals generated based on radio frequency modulation signals output by the controller, and the first optical fiber loop and the second optical fiber loop transmit the light signals emitted by the first light emitting device and the second light emitting device to the first light receiving device and the second light receiving device, respectively, and then the first light receiving device and the second light receiving device convert the light signals into electric signals, respectively, and mix the electric signals with local oscillation signals to form a first mixing signal and a second mixing signal, and the controller calculates an optical path difference according to the first mixing signal and the second mixing signal, thereby obtaining a rotation angle speed.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. The optical fiber gyroscope is characterized by comprising a controller, a light emitting device, a first optical fiber ring, a second optical fiber ring, a first light receiving device and a second light receiving device;

The controller is used for generating a radio frequency modulation signal and a local oscillation signal;

The light emitting device is electrically connected with the controller and is used for emitting light signals according to the modulation signals generated based on the radio frequency modulation signals;

the first optical fiber ring is arranged between the light emitting device and the first light receiving device and is used for transmitting the optical signal emitted by the light emitting device to the first light receiving device;

the second optical fiber ring is arranged between the light emitting device and the second light receiving device and is used for transmitting the optical signal emitted by the light emitting device to the second light receiving device;

The first light receiving device is electrically connected with the controller and is used for receiving the local oscillation signal, converting the optical signal received from the first optical fiber loop into a first electric signal, mixing the first electric signal with the local oscillation signal to form a first mixed signal, and feeding back the first mixed signal to the controller;

the second light receiving device is electrically connected with the controller and is used for receiving the local oscillation signal, converting the optical signal received from the second optical fiber loop into a second electric signal, mixing the second electric signal with the local oscillation signal to form a second mixed signal, and feeding back the second mixed signal to the controller;

the controller is further configured to calculate an optical path difference based on the first mixing signal and the second mixing signal and obtain a rotational angular velocity.

2. The fiber optic gyroscope of claim 1, wherein the controller includes a control element and a phase-locked loop, the control element is electrically connected to the first light receiving device and the second light receiving device, and is configured to receive the first mixing signal and the second mixing signal, and the control element is electrically connected to the phase-locked loop, and is configured to control the phase-locked loop to generate the radio frequency modulation signal and the local oscillation signal.

3. The fiber optic gyroscope of claim 1, further comprising a modulation control circuit connected between the controller and the light emitting device, the modulation control circuit generating the modulation signal based on the radio frequency modulation signal and controlling the light emitting device to emit light via the modulation signal.

4. The fiber-optic gyroscope of claim 1, further comprising a local oscillator processing circuit coupled between the controller and the first light receiving device and between the controller and the second light receiving device, the local oscillator processing circuit configured to process the local oscillator signal.

5. The optical fiber gyro according to claim 1, wherein the first light receiving device includes a first photoelectric conversion element optically coupled to the first optical fiber loop and a first mixing element connected to the first photoelectric conversion element for converting the optical signal transmitted through the first optical fiber loop into the first electrical signal and transmitting the first electrical signal to the first mixing element, the first mixing element further being configured to receive the local oscillation signal and mix the local oscillation signal with the first electrical signal to generate the first mixing signal.

6. The fiber-optic gyroscope of claim 1, further comprising a first filter-amplifier circuit coupled between the first light receiving device and the controller for processing the first mixed signal and a second filter-amplifier circuit coupled between the second light receiving device and the controller for processing the second mixed signal.

7. The fiber-optic gyroscope of claim 1, further comprising a first bias circuit connected between the controller and the first light receiving device for adjusting a bias voltage of the first light receiving device and a second bias circuit connected between the controller and the second light receiving device for adjusting a bias voltage of the second light receiving device.

8. The fiber-optic gyroscope of claim 7, further comprising a first temperature sensor and a second temperature sensor coupled to the controller, the first temperature sensor disposed proximate to the first light receiving device for sensing a temperature of the first light receiving device and the second temperature sensor disposed proximate to the second light receiving device for sensing a temperature of the second light receiving device, the controller controlling the first bias circuit to adjust a bias voltage of the first light receiving device based on the temperature sensed by the first temperature sensor and controlling the second bias circuit to adjust a bias voltage of the second light receiving device based on the temperature sensed by the second temperature sensor.

9. The optical fiber gyro according to claim 1, further comprising a light splitting element provided between the light emitting device and the optical fiber ring for splitting an optical signal emitted from the light emitting device into two optical signals, the two optical signals being transmitted to the first light receiving device via the first optical fiber ring and to the second light receiving device via the second optical fiber ring, respectively.

10. The fiber-optic gyroscope of claim 1, wherein the light emitting device includes a first light emitting device for emitting a first optical signal according to a first modulation signal generated based on the radio-frequency modulation signal, the first optical signal being transmitted to the first light receiving device via the first fiber optic ring, and a second light emitting device for emitting a second optical signal according to a second modulation signal generated based on the radio-frequency modulation signal, the second optical signal being transmitted to the second light receiving device via the second fiber optic ring.