A fiber-optic gyroscope with fast start-up and temperature adaptation

Abstract

The application discloses a fiber-optic gyroscope with quick starting capability and temperature adaptability, comprising a light source, a light source driving and control circuit, a detector I, a beam splitter I, a beam splitter II, a Y waveguide, a fiber ring, a detector II and a differential modulation circuit; the application is used for improving the quick starting capability and temperature performance of the fiber-optic gyroscope, and solves the problems of long starting time and poor temperature adaptability of the high-precision fiber-optic gyroscope. The application focuses on breaking through the design of light control light path and light source driving and control circuit, the design of differential modulation circuit and the design of thermal distribution optimization structure. The application greatly improves the quick starting capability and temperature performance of the gyroscope.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of optical fiber gyroscope with fast starting ability and temperature adaptability, belong to optical fiber gyroscope technical field. BACKGROUND

[0002] Interferometric high-precision fiber-optic gyroscope is a kind of all-solid-state inertial instrument, with high precision, high reliability, long life and other advantages, widely used in missile guidance, aircraft navigation and other fields, the fast starting ability of optical fiber gyroscope and environmental adaptability is particularly important, therefore, it is imminent to improve the fast starting ability and temperature adaptability of optical fiber gyroscope.

[0003] Existing data shows that the starting time of optical fiber gyroscope is related to light source, detector, light source driving and temperature control circuit, internal thermal design of optical fiber gyroscope. Since the detector, light source temperature control circuit, digital closed loop circuit and other components in the optical fiber gyroscope generate heat after power on, which leads to the breaking of internal thermal balance and the process of rebuilding thermal balance, especially the optical fiber ring of sensitive element is a temperature gradient sensitive device, due to the existence of Shupe effect, the positive and negative two beams of light in the optical fiber ring produce non-reciprocal phase difference based on temperature gradient, which finally causes the zero drift of optical fiber gyroscope, when the external temperature changes, it will also cause the zero drift of optical fiber gyroscope. In order to reduce the error introduced by the gyroscope during starting and external temperature change, make the gyroscope quickly reach its own precision, improve the fast stability of gyroscope parameters and temperature environment adaptability. Therefore, from the stability design of optical path and circuit, and the optimization design of structure, so as to realize the fast starting ability and temperature adaptability of optical fiber gyroscope. SUMMARY

[0004] The technical problem of the present application is to overcome the shortcomings of the prior art, and relates to an optical fiber gyroscope with fast starting ability and temperature adaptability, which realizes the fast starting ability and temperature performance of the gyroscope.

[0005] The technical solution of the present application is: an optical fiber gyroscope with fast starting ability and temperature adaptability, comprising: light source, light source driving and control circuit, detector I, beam splitter I, beam splitter II, Y waveguide, optical fiber ring, detector II and differential modulation circuit.

[0006] The light source driving control circuit drives the light source to emit a Gaussian spectrum light signal l1, which is split into two light signals l2 and l3 after entering the beam splitter I; one of the light signals l2 becomes a light signal l4 after passing through the beam splitter II, the light signal l4 enters the interference optical path composed of a Y waveguide and a fiber ring to form an interference signal l5, the interference signal l5 forms a light signal l6 after passing through the beam splitter II and is sent to the detector II, the detector II converts the light signal l6 into a voltage signal and sends it to the differential modulation circuit; the differential modulation circuit receives the voltage signal converted from the light signal l6, processes the signal to generate gyroscope angular velocity information and outputs it to the outside, simultaneously generates a differential modulation signal and a feedback signal and sends them to the Y waveguide, the Y waveguide receives the differential modulation signal and the feedback signal sent by the differential modulation circuit to realize modulation and closed-loop control of the light signal l4; the other light signal l3 reaches the detector I, the detector I converts the light signal l3 into a voltage signal and sends it to the light source driving control circuit; the light source driving control circuit adjusts the light signal l1 to realize control of the light power stability of the light signal l1.

[0007] The light source is a Gaussian spectrum erbium-doped fiber light source.

[0008] The light source, the detector I and the light source driving and control circuit are installed in the same space, the differential modulation circuit and the detector II are installed in another space and are connected to the passive device part composed of the heat insulation plate, the beam splitter I, the beam splitter II, the Y waveguide and the fiber ring, thereby reducing the influence of the internal temperature change of the gyroscope on the light signal.

[0009] The light source driving control circuit drives the light source to generate a light signal l1 and controls the light signal l1 in real time according to the electrical signal generated by the detector I, thereby realizing stable light signal output of the light source.

[0010] The differential modulation circuit comprises a front-end signal processing circuit, an FPGA logic circuit and a Y waveguide control modulation circuit; the detector signal with angular velocity information is converted into an electrical signal digital quantity with angular velocity information through the front-end signal processing circuit, the FPGA logic circuit modulates and demodulates the electrical signal digital quantity to form three signals, namely an angular velocity signal e1, a modulation signal e2 and a gain error signal e3; the angular velocity signal e1 is directly output as a gyroscope signal to the outside; the modulation signal e2 and the gain error signal e3 are sent to the Y waveguide control modulation circuit to generate a feedback analog signal, the feedback analog signal passes through a switching switch to generate a modulation and feedback signal which is sent to the Y waveguide and performs electro-optical modulation on the phase of the Y waveguide, thereby realizing high-sensitivity modulation and closed-loop control of the polarization light signal and completing the closed-loop control loop.

[0011] The output Gaussian spectrum light signal is superfluorescent light in the 1.56±0.02 μm wave band.

[0012] The present application has the following advantages compared with the prior art:

[0013] (1) The present application proposes a light source driving control circuit. The light source part light signal l3 is collected by the detector I, the l3 light power fluctuation when the gyroscope starts and the temperature changes is monitored, the light source driving signal is adjusted by the light source driving control circuit to make the light power of the light signal l3 converge faster when the gyroscope starts and the external temperature changes, so as to control the light power stability of the light signal l1. Avoiding the large fluctuation of the gyroscope light power when starting or the external temperature changes, so as to achieve the purpose of improving the fast start and temperature performance of the gyroscope.

[0014] (2) The present application proposes a differential modulation circuit, which effectively reduces the error introduced into the control loop by the gyroscope when starting and the external temperature changes, so as to make the gyroscope quickly reach its own precision, and at the same time, the decline of the gyroscope zero bias stability caused by the common mode drift of the key parameters of the electronic components is suppressed, and the fast stability and temperature environment adaptability of the gyroscope parameters are improved.

[0015] (3) According to the heat characteristics of the light source, the detector and the electronic components, the light source and the light source driving control circuit are designed as a whole, which is placed at one end of the passive device such as the optical fiber ring, and the other end is connected to the differential modulation circuit and the detector through the heat insulation plate. Heat transfer and heat insulation measures are taken to reduce the influence of the internal heating of the gyroscope on the temperature sensitive parts of the optical fiber ring and other optical paths. In the starting and working process of the gyroscope, the optical path components are in a good thermal environment, so as to realize the stability of the fast start and temperature performance. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a general design scheme diagram of the optical fiber gyroscope of the present application;

[0017] Figure 2 It is a differential circuit design scheme diagram of the optical fiber gyroscope of the present application;

[0018] Figure 3 It is a differential modulation Y waveguide polarity conversion schematic diagram of the present application; DETAILED DESCRIPTION

[0019] As Figure 1 shown, the present application discloses an optical fiber gyroscope with fast start-up capability and temperature adaptability, which comprises an optical control optical path and an optical control light source driving control circuit, a differential modulation circuit and a heat distribution optimization structure.

[0020] The light source emits a light signal 1 1 which enters the beam splitter 1 and becomes two light signals 2 and 3. The light signal 2 passes through the beam splitter 2 and becomes a light signal 4 which enters the interference optical path composed of a Y waveguide and a fiber ring and forms an interference signal 5. The interference signal 5 passes through the beam splitter 2 and becomes a light signal 6 which is sent to the detector 2. At the same time, the light signal 3 reaches the detector 1.

[0021] The light source driving control circuit emits a driving signal to make the light source generate a light signal. The output Gaussian spectrum light signal is superfluorescent in the 1.56±0.02 μm wave band. The light signal enters the beam splitter 1. At the same time, the light signal 3 reaches the detector 1 which converts the voltage signal into an electric signal and sends it to the light source driving control circuit to realize the control of the output light signal.

[0022] As shown in Figure 2 , the differential modulation circuit receives the voltage signal of the detector 2, processes the voltage signal of the detector 2 to generate the gyro angular velocity information, generates a differential modulation signal and a feedback signal at the same time, outputs the gyro angular velocity information to the outside, and sends the differential modulation signal and the feedback signal to the Y waveguide part.

[0023] The light signal output by the light source is split into two beams by the beam splitter 1, passes through the beam splitter 2, the Y waveguide, the fiber ring, and then the Y waveguide again to generate a light signal with angular velocity information. The light signal reaches the detector 2 through the beam splitter 2 and generates an electric signal with angular velocity information through photoelectric conversion and outputs it to the differential modulation circuit. After the modulation and demodulation processing of the electric signal, three signals are formed: the angular velocity signal e1, the modulation signal e2, and the gain error signal e3. The angular velocity signal e1 is directly output as the gyro signal to the outside. The modulation signal e2 and the gain error signal e3 are sent to the digital-to-analog converter 1 of the differential modulation circuit to generate a feedback analog signal. The feedback analog signal passes through the amplification circuit 1 and then passes through the switch as shown in Figure 3 to generate the modulation and feedback signals which are sent to the Y waveguide of the optical path part to electrically and optically modulate the phase of the Y waveguide, realize the high-sensitivity modulation and closed-loop control of the polarized light signal, and complete the closed-loop control circuit.

[0024] The heat distribution optimization structure is that the light source, the detector 1, the light source driving and control circuit are installed in the same space, the differential modulation circuit and the detector 2 are installed in another space, and they are connected through the heat insulation plate with the passive device part composed of the beam splitter 1, the beam splitter 2, the Y waveguide and the fiber ring, respectively. The optical path part and the circuit part are separated and relatively independent. When the gyro is started, the heat generated by the light source, the detector and the circuit can be evenly distributed around the fiber ring to realize the rapid start of the gyro. At the same time, the influence of the change of the external environment temperature is effectively reduced to improve the temperature environment adaptability of the gyro.

[0025] The working principle of the light source driving control circuit in the fiber-optic gyroscope of the present application is as follows:

[0026] The light signal l3 is collected by the light source driving control circuit and the detector I to monitor the fluctuation of the light power of l3 when the gyroscope is started and when the temperature changes. The light source driving signal is adjusted by the light source driving control circuit to make the light power of the light signal l3 converge more quickly when the gyroscope is started and when the temperature changes, so as to control the stability of the light power of the light signal l1. The fluctuation of the light power of the gyroscope when it is started or when the temperature changes is avoided, so as to improve the fast starting and temperature performance of the gyroscope.

[0027] The working principle of the differential modulation circuit of the present application is as follows:

[0028] The electrical signal e2 of the modulation channel is applied to the positive and negative electrodes of the Y waveguide of the fiber-optic gyroscope. When the polarity of the voltage applied to the two electrodes of the Y waveguide changes, the scale factor of the fiber-optic gyroscope changes symmetrically in positive and negative directions, which is equivalent to the forward and reverse rotation of the fiber-optic gyroscope. The differential output controls the polarity conversion of the Y waveguide to reduce the error introduced into the control loop when the gyroscope is started and when the temperature changes.

[0029] By controlling the polarity conversion of the Y waveguide, the gyroscope can quickly reach its own precision, and at the same time, the decrease of the zero bias stability of the gyroscope caused by the common-mode drift of the key parameters of the electronic components can be suppressed, and the fast stability of the gyroscope parameters and the temperature environment adaptability can be improved. The schematic diagram of the polarity conversion of the Y waveguide is shown in Figure 3 .

[0030] The heat distribution optimization structure of the present application: for the three ways of heat transfer: heat conduction, heat convection and heat radiation, corresponding heat transfer and heat insulation measures are taken respectively to reduce the influence of the internal heating of the gyroscope on the light path sensitive parts such as the fiber ring. On the one hand, the light source and the light control circuit are designed as a whole and are placed at one end of the passive devices such as the fiber ring, and the other end of the differential modulation circuit and the detector is connected to it through a heat insulation plate, so that the light path components are in a good thermal environment during the starting and working process of the gyroscope, thereby realizing the stability of the fast starting and temperature performance. On the other hand, the light source driving control circuit part, the light path part and the differential circuit part of the fiber-optic gyroscope are separated and relatively independent, without contact conduction or with heat insulation material parts installed on the contact surface, so as to reduce heat conduction, and at the same time, the structure blocks the heat convection and heat radiation, avoiding the influence of the internal heating of the gyroscope on the light path components of the fiber-optic gyroscope.

[0031] The starting time of the high-precision gyroscope without the improvement of the application is 10 minutes, and the starting time of the high-precision gyroscope with the improvement of the application is not more than 30 seconds, and under the same temperature change condition, the temperature performance is improved by 20%, so it can be seen that the design of the application can improve the starting ability and temperature performance of the high-precision gyroscope. The contents not described in detail in the specification of the application belong to the known technology of the professional technical personnel in the field.

Claims

1. A fiber-optic gyroscope with fast start-up capability and temperature adaptation capability, characterized in that, It comprises: a light source, a light source driving and control circuit, a detector I, a beam splitter I, a beam splitter II, a Y waveguide, a fiber ring, a detector II and a differential modulation circuit; The light source driving and control circuit drives the light source to emit a Gaussian spectrum light signal l1, which is divided into two light signals l2 and l3 after entering the beam splitter I; One of the light signals l2 becomes a light signal l4 after passing through the beam splitter II, and the light signal l4 enters an interference light path composed of the Y waveguide and the fiber ring to form an interference signal l5, which becomes a light signal l6 after passing through the beam splitter II and is sent to the detector II, which converts the light signal l6 into a voltage signal and sends it to the differential modulation circuit; The differential modulation circuit receives the voltage signal converted from the light signal l6, processes the signal to generate gyroscope angular velocity information and outputs it to the outside, and simultaneously generates a differential modulation signal and a feedback signal to be sent to the Y waveguide, which receives the differential modulation signal and the feedback signal sent by the differential modulation circuit to realize modulation and closed-loop control of the light signal l4; the other light signal l3 reaches the detector I, which converts the light signal l3 into a voltage signal and sends it to the light source driving and control circuit; the light source driving and control circuit adjusts the light signal l1 to realize control of the light power of the light signal l1. The differential modulation circuit comprises a front-end signal processing circuit, an FPGA logic circuit and a Y waveguide control modulation circuit; the detector signal with angular velocity information is converted into an electrical signal digital quantity with angular velocity information by the front-end signal processing circuit, and the FPGA logic circuit modulates and demodulates the electrical signal digital quantity to form three signals, i.e. an angular velocity signal e1, a modulation signal e2 and a gain error signal e3; wherein the angular velocity signal e1 is directly outputted as a gyroscope signal to the outside; the modulation signal e2 and the gain error signal e3 are simultaneously sent to the Y waveguide control modulation circuit to generate a feedback analog signal, which is converted into a modulation and feedback signal by a switching switch and sent to the Y waveguide to electrically and optically modulate the phase of the Y waveguide, realize high-sensitivity modulation and closed-loop control of the polarized light signal, and complete the closed-loop control circuit.

2. The fiber-optic gyroscope with fast start-up capability and temperature adaptation capability according to claim 1, characterized in that: The light source is a Gaussian spectrum erbium-doped fiber light source.

3. The fiber-optic gyroscope with fast start-up capability and temperature adaptation capability according to claim 1, characterized in that: The light source, the detector I and the light source driving and control circuit are installed in the same space, the differential modulation circuit and the detector II are installed in another space, and are connected to the passive device part composed of the beam splitter I, the beam splitter II, the Y waveguide and the fiber ring through the heat insulation plates, thereby reducing the influence of internal temperature changes of the gyroscope on the light signal.

4. The fiber-optic gyroscope with fast start-up capability and temperature adaptation capability according to claim 1, characterized in that: The light source driving and control circuit controls the light signal l1 in real time according to the electrical signal generated by the detector I while driving the light source to generate the light signal l1, thereby realizing stable output of the light source.

5. The fiber-optic gyroscope with fast start-up capability and temperature adaptation capability according to claim 1, characterized in that: The Gaussian spectrum light signal is super-fluorescent in the 1.56±0.02 μm waveband.

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