145 results about "Fiber optical gyroscope" patented technology

The invention aims at providing a novel CKF(Crankshaft Fluctuation Sensor)-based SINS (Ship Inertial Navigation System) large misalignment angle initially-aligning method comprising the following steps of: determining an initial position parameter of a carrier by using a GPS (Global Position System); acquiring data output by an optical fiber gyroscope and a quartz accelerometer; finishing the coarse alignment of the system by using an analysis method; preliminarily determining the posture information of the carrier; establishing an initial aligning nonlinear model of a strapdown inertial navigation system; establishing a CKF filtering state equation by taking the speed error as the state variable and a measuring equation by taking the speed error as the measurement quantity under a static base; carrying out filtering estimation by using a CKF filtering method to estimate the misalignment angle of the platform; and obtaining an accurate strapdown initial posture matrix by using a strapdown initial posture matrix of a platform misalignment angle correcting system, thereby finishing the accurate initial alignment. The invention can greatly improve the aligning precision of the strapdown inertial navigation system at the large misalignment angle and provide the accurate strapdown initial posture matrix for the navigation process.

The invention firstly provides a multi-stage control device for the dynamic tension of an optical fiber winding machine. The device comprises a paying-off wheel and a taking-up ring and further comprises a guide wheel A and a guide wheel B. The paying-off wheel, the guide wheel A and the guide wheel B are fixedly arranged in sequence from left to right. The taking-up ring is movably arranged at the tail end of the right side. A tensioning wheel capable of vertically moving is arranged between the guide wheel A and the guide wheel B. The lower portion of the tensioning wheel is sequentially and fixedly connected with a tension and pressure sensor and a micromechanism. The tensioning wheel and the tension and pressure sensor can vertically move at the same time through the micromechannism. The paying-off wheel is connected with a paying-off wheel motor. The micromechanism, the tension and pressure sensor and the paying-off wheel motor are connected with an upper computer. The invention further provides a multi-stage control device for the dynamic tension of the optical fiber winding machine. The multi-stage control technology is adopted, the control precision of the tension of an optical fiber and the quality of an optical fiber loop are improved, it is effectively guaranteed that the optical fiber loop is evenly wound, and the requirement of a high-precision optical fiber gyroscope is met.

A fiber optic ring interferometer, such as an interferometric fiber optic gyro (IFOG), with a sensing loop doubler. The IFOG device includes a light source, a circulator in optical communication with the light source and a photo diode, an integrated optical chip (IOC) capable of splitting light emitted from the circulator into two paths each of which is capable of being modulated, the IOC further being capable of combining light from each of the two paths when light travels in a direction towards the circulator, a fiber coil, and a polarization maintaining (PM) combiner/splitter disposed in between the IOC and the fiber coil. The PM combiner/splitter operates to send light through the fiber coil a first time in a first polarization state and to subsequently send the same light a second time through the fiber coil in a second orthogonal polarization state, whereby light travels twice the distance compared to a single loop IFOG device and, as such, effectively doubles the LD product.

The invention discloses a method for restraining speed errors of a single-shaft rotation optical fiber gyro strapdown inertial navigation system. The method comprises the following steps of: 1. acquiring carrier position information through a global positioning system (GPS); 2. acquiring data output by an optical fiber gyro and a quartz accelerometer; 3. driving an inertial component to perform single-shaft forward and backward rotation and stop motion by a rotary mechanism, and adopting a rotation scheme that eight rotation and stop sequences are used as a rotation period; 4. acquiring information of linear velocity and angular velocity of the motion of measurement carriers of the optical fiber gyro and the quartz accelerometer, and performing navigation solution to obtain navigation information; and 5. constructing a Butterworth band elimination filter, and performing Butterworth filter processing on the carrier velocity obtained under a navigation system. According to the method, the Butterworth band elimination filter is designed according to the rotation angular velocity, oscillation error items related to the rotation angular velocity under the navigation system are filtered and removed, and the velocity information accuracy is improved.

A photonic crystal interferometric optical gyroscope system including a light source for providing a primary beam of light, a photonic crystal sensing coil having a rotational axis, and a beam controlling device configured to split the primary beam into first and second counter-propagating beams in the photonic crystal sensing coil and configured to direct return of the counter-propagating beams wherein the power of the returning counter-propagating beams represents the phase shift between the counter-propagating beams and is indicative of the rate of rotation of the coil about the rotational axis.

The invention discloses a method for reducing temperature sensitivity of optical fiber gyroscope scale factors without a refrigerating light source. The method comprises the following steps of: removing a light source refrigerating circuit from an optical fiber gyroscope, controlling the temperature of the light source of the optical fiber gyroscope via an incubator according to a series of pre-selected temperature points, measuring the average wavelength of the light outputted from the light source with a spectrometer to obtain a table of the average wavelength and the temperature points, and placing the table into a memorizer of a table look-up module in correction step; adding average wavelength correction step, real-time collecting a temperature signal with a thermometer, looking up the table to obtain the average wavelength value under certain temperature according to the temperature signal, and performing average wavelength correction to the original output data of the optical fiber gyroscope according to the value. The corrected data is used as new output data of the optical fiber gyroscope, and the scale factor of the new output data is irrelevant to the average wavelength, so as to reduce the temperature sensitivity of the scale factor of the optical fiber gyroscope without refrigerating light source, thereby simplifying the system, reducing power consumption and heating value, improving the internal thermal environment, and improving the reliability.

The invention provides an integrated attitude determination method without external observed quantity for a modulated strapdown system. The method comprises the steps of: determining initial position parameters of a carrier by a global positioning system (GPS) and binding the parameters to a navigation computer; acquiring data output by a fiber optic gyros and a quartz accelerometer, and processing the data; setting an inertial measurement unit (IMU) single shaft four position rotation stopping scheme; converting the accelerometer output to a carrier semi-fixed coordinate system; designing an infinite impulse response (IIR) digital high-pass filter, and carrying out filtering on the carrier velocity resolved under a navigation system; subtracting the filtered velocity from a velocity calculated by the modulated strapdown system, and using the difference as a system observed quantity; and estimating attitude information of the modulated strapdown inertial navigation system by a Kalman filtering technique. The method provided by the invention does not need external auxiliary equipment to provide observation information, and can effectively solve the problem of mismatching between the frequency of information supply by the auxiliary equipment and the frequency of cultivation of the modulated strapdown system, and realize integrated attitude determination of the modulated strapdown inertial navigation system.

The invention aims to provide a high-precision interference type optical fiber gyroscope temperature drift error model optimizing method. According to the method, optical fiber ring temperature product quantity T*delta T, optical fiber ring temperature T and optical fiber ring temperature variable quantity delta T jointly serve as optimal input quantities of an interference type optical fiber gyroscope temperature drift error basic model, and an interference type optical fiber gyroscope temperature drift error optimization model is realized by adopting RBF-ANN; a temperature drift error measured value is obtained by a temperature increasing and reducing test, a temperature drift error estimated value is obtained by estimating an optimization model, and the precision of the optimized model is verified by comparing the temperature drift error measured value and the estimated valve. According to the method, the adopted optimal input quantities are more integral, the temperature drift error model is described more precisely, the accuracy, the real-time property and the universality of interference type optical fiber gyroscope temperature drift error estimation are improved, and the stability and the reliability of output data of the interference type optical fiber gyroscope are guaranteed.

The invention discloses an optical fiber strapdown inertial navigation high-precision positioning system and method for an underwater bathyscaph. The optical fiber strapdown inertial navigation high-precision positioning system comprises a navigation solution module, a global positioning system module, a strapdown inertial navigation receiving module, a Doppler speed-measuring module and an information fusion filtering module. An optical fiber gyroscope, an accelerometer and a magnetometer in the strapdown inertial navigation receiving module output the navigation attitude, the speed and position initial information, data output by the optical fiber gyroscope are subjected to error processing and correction through a dynamic Allan variance method, the processed data pass through the navigation solution module to obtain the velocity, position and attitude information of a carrier, finally the velocity information of the carrier is subjected to fusion and filtering error correction through the information fusion filtering module, and thus the underwater bathyscaph is precisely positioned. High-precision, high-reliability and high-real-time-property positioning and navigation of the underwater bathyscaph are achieved, and the deficiency of accuracy of position information of a traditional navigation system is overcome.

The invention provides a fiber optic acoustic wave sensing cross-dipole acoustic wave well-logging system and a measurement method thereof. The fiber optic acoustic wave sensing cross-dipole acousticwave well-logging system comprises an in-well fiber optic acoustic wave sensing cross-dipole acoustic wave well-logging device, the in-well fiber optic acoustic wave sensing cross-dipole acoustic wavewell-logging device comprises a cylindrical structure instrument shell and a fiber optic acoustic wave dipole sensor; and a fiber optic gyroscope, a sound insulation body short section and a dipole acoustic source generator are perpendicularly and sequentially mounted on the lower part of the fiber optic acoustic wave dipole sensor. A ground wellhead well-logging vehicle controls going down intoa well and rising from the well of the in-well fiber optic acoustic wave sensing cross-dipole acoustic wave well-logging device, provides a power supply for the in-well fiber optic acoustic wave sensing cross-dipole acoustic wave well-logging device, and drives the dipole acoustic source generator to continuously and repeatedly emit a dipole acoustic wave signal during operation; and a ground DASmodulation and demodulation instrument emits a laser pulse into the fiber optic acoustic wave dipole sensor, and collects a backscattering rayleigh wave inside the fiber optic acoustic wave dipole sensor. The fiber optic acoustic wave sensing cross-dipole acoustic wave well-logging system can work for a long time at the high temperature and realize the function of high-speed upward-transmission ofdata.

The present invention provides a novel detection method of an optical fiber gyroscope, wherein the detection ports are a reciprocal port (I port) and a nonreciprocal port (II port) of an interferometric depolarization fiber optic gyroscope, and the signal processing adopts the differential signal processing manner. The method comprises that: the optical structure of the interferometric depolarization fiber optic gyroscope for testing requires that lyot depolarizers are respectively added between the light source and the light source coupler, the light source coupler and the optical fiber ring coupler, and the optical fiber ring coupler and the optical fiber ring, the phase modulation adopts the sine signal having optical fiber gyroscope eigenfrequency, the amplitude of the sine signal is correspondingly adjusted so as to make the modulation depth value be stabilized to near 1.841, a dual-channel photoelectrically balanced detector is utilized to concurrently detect the reciprocal port (I port) and the nonreciprocal port (II port) of the interferometric depolarization fiber optic gyroscope, the two electrical signals being subjected to photoelectric conversion are subjected to normalization and then are subjected to a differential treatment, and the differential result is utilized to demodulate the gyroscope signal. With the method of the present invention, the random walk of the optical fiber gyroscope can be effectively reduced, and the zero-bias stability of the optical fiber gyroscope can be improved.

The invention provides an error suppressing method of a fiber strap-down inertial navigation system based on three-axis rotation. The error suppressing method comprises the following steps: determining an initial position parameter of a carrier by using a GPS (global positioning system); collecting data output by a fiber-optic gyroscope and a quartz accelerometer; determining attitude information of the carrier according to relationship of output of the accelerometer and gravity acceleration as well as relationship of output of the gyroscope and the rotational angular velocity of the earth, and accomplishing initial alignment of the system; employing an indexing scheme of a rotational period of twelve rotation-stop orders by IMU (inertial measurement unit); converting data generated by the fiber-optic gyroscope and the quartz accelerometer after rotation of the IMU to be in navigation coordinate system to obtain a modulation format of constant deviation of an inertial unit; updating a strap-down matrix by utilizing an output value of the fiber-optic gyroscope; and calculating position information of the carrier after the IMU is rotated and modulated. With the adoption of the error suppressing method disclosed by the invention, constant deviation of the inertial unit in three-axis direction can be modulated, thereby navigation positioning precision is improved.

A resonator fiber optic gyroscope (RFOG) is provided. The RFOG includes a gyroscope resonator having a clockwise input port and a counter-clockwise input port; a first laser configured to couple a clockwise optical beam into to the clockwise input port; a clockwise Pound-Drever-Hall modulation generator to modulate the clockwise optical beam with a resonance tracking modulation before the clockwise optical beam is coupled into the clockwise input port; bias correction electronics; FSR-detection-and-servo electronics including a switch communicatively coupled to the clockwise Pound-Drever-Hall modulation generator; a clockwise transmission detector configured to receive an optical beam output from the counter-clockwise input port and output signals to the bias correction electronics and the FSR-detection-and-servo electronics; and a second laser configured to couple a counter-clockwise optical beam into to the counter-clockwise input port, wherein the FSR of the gyroscope resonator is measured based on the Pound-Drever-Hall modulation of the clockwise optical beam.

The invention discloses an off-line wavelet denoising fast initial alignment method which has the advantages that the initial coarse alignment time of a high-precision strapdown inertial system is further reduced, and the accuracy is further improved. The method comprises the following steps of (1) acquiring sensor data comprising data of an optical fiber gyroscope and a quartz flexible accelerometer; (2) establishing initial alignment coordinate systems comprising an initial carrier coordinate system, an initial navigation coordinate system, an initial earth coordinate system, a carrier coordinate system, a navigation coordinate system, an earth coordinate system and an inertial coordinate system; (3) establishing a gravity apparent motion vector model, and constructing an off-line wavelet denoising algorithm; (4) utilizing a gravity apparent motion vector subjected to denoising and filtering for calculating an optimum initial attitude; (5) utilizing the calculated optimum initial attitude quaternion and using an attitude matrix chain rule to realize a fast initial alignment process. According to the off-line wavelet denoising fast initial alignment method provided by the invention, the calculation accuracy and the efficiency of an initial alignmentalgorithm are effectively improved, and the application range is wide.

The invention discloses a spraying teaching device which adopts machine vision and optical fiber gyroscope to coordinate positioning. It includes a teaching powder room, a spray gun device is arranged on the teaching powder room, and a first The camera, the top of the teaching powder room is provided with a second camera, the spray gun device is provided with a fiber optic gyroscope for collecting the attitude of the teaching spray gun, and the fiber optic gyroscope is connected with an external multi-axis controller; by using the first camera and the second camera Instead of the complex mechanical mechanism in the prior art to obtain the coordinate parameters of the spray gun device, the fiber optic gyroscope is used to obtain the attitude parameters of the spray gun device, and the multi-axis controller obtains the coordinate parameters and the attitude parameters and drives the manipulator to reproduce the operation process of the teaching mechanism , which can solve the current multi-axis manipulator's complex teaching methods and high technical requirements, improve the flexibility of the multi-axis manipulator's spraying operation mode, and achieve the purpose of simplifying the teaching equipment structure, reducing production costs, improving equipment flexibility and expanding the scope of work.

The invention belongs to the technical fields of optical fiber sensing and inertial navigation, and relates to a closed loop fiber-optical gyroscope temperature compensating method. The closed loop fiber-optical gyroscope temperature compensating method is characterized in that a Y waveguide half-wave voltage substitutes temperature information to carry out temperature compensation on a closed loop fiber-optical gyroscope by using the approximate linear relationship between the Y waveguide half-wave voltage change and the temperature change of the closed loop fiber-optical gyroscope, and a four state modulation-based double-loop closed loop fiber-optical gyroscope is used to extract the change information of the waveguide half-wave voltage with the temperature in real time in order to realize the temperature sensor-free closed loop fiber-optical gyroscope temperature compensation. The method simplifies the design of software and hardware of a circuit, further reduces the size of the gyroscope, increases the compensation precision, has the characteristics of simple realization method, low cost and high reliability, and is of great significance to increase the temperature change precision of the fiber-optical gyroscope and further expand the application field of the fiber-optical gyroscope.

The invention discloses an angular displacement optical fiber gyroscope, which comprises an optical path part and a circuit part. The optical path part consists of an optical fiber ring, a Y waveguide, a coupler, an optical source and a detector; in the optical path part, an optical signal generates phase shifting through a Sagnac effect; the phase-shifting signal parasitizes in interference optical intensity and is converted and output as a detector signal (electric signal) by the detector; in the circuit part, the detector signal output by the detector is subjected to signal amplification and conversion through a preliminary amplifier and an analog-to-digital conversion circuit; and the circuit part also comprises a circuit resolving unit logic circuit; the circuit resolving unit logic circuit resolves the rotation angle information of the optical fiber gyroscope through carrying out digital signal demodulation, digital filtering and integral treatment on the amplified and converted detector signal, judges and outputs an angle direction. The angular displacement optical fiber gyroscope has the advantages that a program, logic and the like for processing the signal in the circuit part are innovated and improved, so that the optical fiber gyroscope has an angular displacement output function.

An integrated biplane optical sensing core chip has a non-linear optical substrate, a first waveguide structure, a second waveguide structure and a waveguide coupled fiber. The non-linear optical substrate, the first waveguide structure and the second waveguide structure are made of the same nonlinear optical material. The first waveguide structure is connected to the second waveguide structure via a waveguide coupled fiber is outside and independent to the non-linear optical substrate. Therefore, the first waveguide structure and the second waveguide structure can overlap in the vertical direction, and can be set close to each other in the horizontal and vertical directions, so the integrated biplane optical sensing core chip can be miniaturized and can meet reciprocity. The integrated biplane optical sensing core chip is suitable for an optical fiber sensor, and the optical fiber sensor can be a fiber-optic gyroscope or a fiber-optic current sensor.

The invention relates to a self-adaptive initial alignment method of a ship strapdown inertial navigation system. The self-adaptive initial alignment method comprises the following steps: enabling a ship SINS(Ship Inertial Navigation System) to begin to work, and acquiring measured information of a fiber-optical gyroscope and an accelerometer; providing an initial location of a ship according to aglobal positioning system carried by the ship as well as the acquired fiber-optical gyroscope and accelerometer information, primarily determining attitude information of the ship by utilizing a parsing-type coarse alignment algorithm, and completing the coarse alignment of the ship SINS; establishing a nonlinear error model of the ship SINS in a high-dynamic environment; establishing a nonlinearfilter equation in the high-dynamic environment of the ship; estimating the system noise by utilizing a VCE-based self-adaptive CKF algorithm in real time, and estimating a misalignment angle of thesystem; and correcting an initial strapdown attitude matrix of the system by utilizing the misalignment angle estimated in step 5, obtaining a precise initial strapdown matrix, and completing a precise alignment process under a movable foundation bed. By adopting the method, the nonlinear problem and uncertain noise problem in the initial alignment of the inertial navigation system can be solved,and the alignment comprehensive performance can be effectively improved.

An octupole winding pattern for winding a fiber optic coil includes at least two layers of an eight-layer winding pattern having an end fiber optic coil diameter formed in an opposite direction as a substantial portion of a remaining portion of the respective layer. The selectively arranged octupole winding pattern may be used in a fiber optic gyroscope. A spool onto which the fiber optic coil is wound may be removable. Preferably, the octupole winding pattern is advantageously arranged to provide a substantial amount of optical symmetry with respect to a winding centerline of the fiber optic coil. In addition, the octupole winding pattern provides a substantial amount of geometric, mechanical, and thermal symmetry.

The technical solution provides a demodulation integral circuit for angular rate of an optical fiber gyroscope, which comprises an inverter, an integrator, a sampler, a first switch SW1, a second switch SW2 and a switch controller, wherein the input end of the inverter is the input end of the demodulation integral circuit; the first switch SW1 is connected between the input end of the inverter and the input end of the integrator, and the input end of the integrator is further connected to the output end of the inverter; the second switch SW2 is connected between the output end of the inverter and the input end of the integrator, the output end of the integrator is connected to the input end of the sampler, and the output end of the sampler is used as the output end of the demodulation integral circuit; the sampler comprises a third switch, and the switch controller controls the on and off of the first switch SW1, the second switch SW2 and the third switch. According to the invention, the demodulation integral for an angular rate signal of the optical fiber gyroscope is realized. Compared with the prior art, the size of an optical fiber gyroscope circuit part is reduced, the cost of a circuit part is reduced, and the loss of original data is avoided.