889results about "Sagnac effect gyrometers" patented technology

The invention provides a fiber-optic gyroscope drift compensation method and system fused with LMS self-adaptive filtering, and relates to the technical field of LMS self-adaptive filtering, the method comprises the following steps: synchronously collecting multi-point temperature data, temperature change rate, axial and radial gradient information and original output signals of a gyroscope shell, and calculating the multi-point temperature data, the temperature change rate, the axial and radial gradient information and the original output signals of the gyroscope shell; the original signal is separated into a temperature drift component and a non-temperature noise component through variational mode decomposition, and noise is filtered out; establishing a nonlinear mapping relation by combining the temperature field data and the drift component to generate a drift predicted value, and inputting the predicted value and the residual error of the actual drift component into an LMS adaptive filter for dynamic error compensation; and finally, superposing the compensation result and the predicted value, and outputting a corrected gyro signal. According to the invention, the drift compensation precision and stability of the fiber-optic gyroscope in a complex variable-temperature environment are improved.

The invention relates to the technical field of optical fiber sensing and fault diagnosis, in particular to an optical fiber gyroscope fault monitoring method and system. The method comprises the following steps: extracting four-dimensional characteristics of phase difference, light intensity fluctuation, polarization state drift and temperature drift from an output signal of an optical fiber gyroscope, and constructing a high-dimensional characteristic matrix after unifying a time reference; establishing a dynamic prediction model based on historical data to generate a residual matrix, and orthogonally separating the residual into an internal structure abnormal signal and an environment disturbance signal through covariance characteristic decomposition; mapping the structure residual error sequence into a topological graph, calculating an evolution index in real time, and capturing a fault gradient trend in combination with sliding window gradient analysis; a multi-dimensional vector is constructed by fusing topological features, an adaptive classifier of an online Gaussian mixture model is adopted to identify a fault mode and quantify a health index, and meanwhile, a health measurement result is fed back to a prediction model and topological analysis parameters to realize closed-loop optimization. According to the invention, full-process adaptive monitoring from anomaly detection to health measurement is realized.

The invention discloses an airborne combined measurement calculation method for closed-loop optical fibers, which comprises the following steps that: an orthogonally distributed three-axis closed-loop optical fiber gyroscope array acquires a Sagnac phase difference signal in real time, each optical fiber ring adopts an asymmetric pretightening force winding process, the pretightening forces of X / Y / Z axes are 12 + / -0.5 N, 8 + / -0.3 N and 15 + / -0.5 N respectively, the diameter ratio of the optical fiber rings is 1: 0.8: 1.2, environmental disturbance compensation is carried out, and the Sagnac phase difference signal is acquired in real time. Data of 48 PT1000 temperature sensors embedded in the axial direction of an optical fiber ring at the interval of 5 mm and full spectrum data of a three-axis vibration sensor at the frequency band of 0-2000 Hz are synchronously collected, and a coupling error model is constructed based on temperature gradient distribution and vibration spectrum characteristics. Therefore, through an asymmetric winding process, temperature-vibration coupling compensation, improved data fusion and dynamic closed-loop control, the problems of nonreciprocal errors caused by the symmetric winding process, insufficient environmental adaptability of single temperature compensation, limited nonlinear error processing capability of standard Kalman filtering and stability of a fixed parameter controller are solved; high-precision and high-reliability airborne combined measurement is realized.

The invention provides an orbital angular momentum interferometer based on a double-resonance spiral long-period fiber grating and application, and belongs to the field of optical fiber sensing and optical communication passive devices. According to the invention, the double-resonance spiral long-period fiber grating is used as an OAM mode converter, the wavelength of the laser is secondarily regulated and controlled to match left and right resonance peaks, phase superposition of conjugate OAM beam pairs is realized, and secondary sensitization of the OAM interferometer is realized based on a single mode converter. The OAM interferometer is applied to the field of temperature and strain sensing, high-sensitivity detection of temperature variation and strain variation is achieved by combining a double-phase matrix decoupling algorithm, and the problem of cross sensitivity is effectively solved. The invention provides an all-fiber integrated and environment interference resistant innovative solution for high-sensitivity OAM optical fiber sensing, and is suitable for the fields of industrial monitoring, environment sensing and optical communication.

A fiber optic gyroscope temperature drift modeling and real-time compensation method is provided, and the specific steps are as follows: Step 1: Design a fiber optic gyroscope temperature test, and collect the fiber optic gyroscope output value and the fiber optic gyroscope internal temperature sensor data within the full temperature range of ‑30° to 70°; Step 2: Perform wavelet threshold denoising preprocessing on the fiber optic gyroscope output obtained in step 1; Step 3: Establish a fiber optic gyroscope temperature drift segmented compensation model F with temperature change and temperature gradient as independent variables and the fiber optic gyroscope output signal after wavelet threshold denoising preprocessing as the dependent variable; Step 4: Calculate the coefficient of the temperature compensation model F by the least squares method and compensate the fiber optic gyroscope output in real time. The present invention meets the requirements of fast calculation speed and simplicity in engineering, meets the requirements of real-time compensation in engineering, and can effectively solve the problem of fiber optic gyroscope temperature drift, thereby improving the accuracy of the fiber optic gyroscope.

The invention belongs to the technical field of micro photoelectric mechanical systems and micro inertial devices, and particularly relates to a cascaded Fabry-Perot cavity-based ultra-wide optical bandwidth MOEMS gyroscope, which comprises a mass block, an optical structure, an anchoring structure, an electrostatic comb-shaped driving structure, a detection frame, an anchoring frame, an induction spring, a driving spring and a driving frame, the mass block is connected with the optical structure, anchoring structures are arranged at the four corners of the mass block respectively, electrostatic comb-shaped driving structures are arranged on the two sides of the mass block respectively, detection frames are connected to the two sides of the mass block respectively, and the mass block is connected with the anchoring frames through induction springs. On the basis of the Coriolis force measurement principle, the angular velocity is measured by detecting the wavelength or intensity change of an output harmonic peak caused by the structural change of the cascade cavity. Benefited from broadband tuning characteristics and high compactness of a cascade cavity structure, the device can be used in an optical bandwidth range exceeding 175 nm, and has a highly compact structure consisting of an all-silicon micro waveguide and a cavity.

The utility model discloses an auxiliary cavity adjusting device for a laser gyroscope, which comprises a He-Ne laser, a collimation laser, an adjustable first reflecting mirror, a semi-transparent semi-reflecting mirror, a second reflecting mirror, a third reflecting mirror, an imaging mechanism and a light beam coincidence verification structure, and is characterized in that the collimation laser is arranged on the right side of a cavity to be adjusted and corresponds to a left upper plane mirror of the cavity to be adjusted; the first reflecting mirror and the third reflecting mirror are located between the cavity to be adjusted and the collimating laser, the semi-transparent and semi-reflecting mirror is located between the second reflecting mirror and the He-Ne laser, the light beam coincidence verification structure is movably located between the semi-transparent and semi-reflecting mirror and the second reflecting mirror, the He-Ne laser is located right above the collimating laser, and the He-Ne laser is located right above the collimating laser. The semi-transparent semi-reflecting mirror is located over the first reflecting mirror, the second reflecting mirror is located over the third reflecting mirror, and the imaging mechanism is located on the right side of the cavity to be adjusted and corresponds to a left lower plane mirror of the cavity to be adjusted. According to the utility model, the cavity adjusting efficiency and accuracy of the laser gyroscope can be improved.

The invention relates to the technical field of optical fiber gyroscopes, in particular to a temperature control optical fiber inertial navigation structure and a design method thereof.The design method comprises the following steps of detecting heat flow direction changes, extracting offset numbers, generating frequency density, analyzing the thickness contour and deformation coincidence rate, outputting correction gradients, matching jump trends and structural connection, and generating a priority sequence; and screening offset channel numbers, integrating compression and deformation trends, and outputting a design scheme. According to the method, by capturing heat flow direction change points and extracting offset area numbers, density expression of a heat energy propagation path is achieved, the space recognition capability of thermal disturbance is enhanced, the structural adaptability of thermal response is improved, and stable conduction of heat flow between structural levels is optimized through sequence integration of a temperature jump trend and a connection relation; and extracting a stable channel number in a lateral offset state, enhancing path directivity, integrating a multi-region compression trend and structural deformation mapping, and improving thermal situation identification capability and structural thermal adaptability.

The invention relates to the technical field of perception fusion, and discloses a tug fusion enhanced perception method based on target tracking and obstacle recognition, which comprises the following steps: processing an AIS, an optical fiber compass, a Beidou RTK, a laser radar, a millimeter wave radar and a panoramic camera on a tug to establish a ship coordinate system; and collecting message data of the AIS and combining with the MMSI information to screen the target ship to obtain the initial position of the target ship. And predicting the state sequence of the target ship to obtain the position, speed and heading information of the target ship. And carrying out target identification on the image, outputting identification results of semantic levels of the ship, the buoy and the quay wall, and carrying out space projection alignment with radar data. And fusing the processed results to obtain a fusion result, and performing early warning according to the fusion result. According to the method, the target ship relative pose resolving precision and the obstacle recognition reliability are improved, the sensing link time delay is shortened, and the driver blind area risk is reduced.

The invention belongs to the technical field of optoelectronic devices, and provides a laser gyroscope frequency stabilization system and a frequency stabilization method thereof.The laser gyroscope frequency stabilization system comprises a large laser gyroscope to be subjected to frequency stabilization, an electro-optical modulator, an adjusting light path, a signal generator, a mode matching mirror set, a PID regulator, a frequency mixer, a photoelectric detector, an ultra-stable cavity, a low-pass filter, a computer and a data acquisition card; and a square transmission light path is arranged in the ultra-stable cavity. According to the invention, the problem of insufficient isolation caused by an optical isolator consisting of a polarization splitting prism and a 1 / 4 wave plate is effectively avoided, the influence of an optical feedback effect is reduced, and the optical isolator is better adapted to the field of high-precision measurement related to a large laser gyroscope.

The invention discloses a method for reducing an angle measurement error of a fiber-optic gyroscope under a launching load. The method comprises the following steps: establishing a full-gun finite element dynamic model; correcting dynamic model parameters based on the seat ring test acceleration data; establishing a fiber-optic gyroscope mounting platform angular acceleration response maximum pulse value and pulse width prediction model taking a firing angle as an input variable by adopting an approximate modeling technology, and predicting the fiber-optic gyroscope mounting platform angular acceleration response maximum pulse value and pulse width corresponding to firing data; establishing a three-axis fiber-optic gyroscope zero offset increment prediction model under a half-sine angular acceleration impact load by adopting an angular impact test platform calibration method, and predicting the fiber-optic gyroscope zero offset increment corresponding to the obtained maximum pulse value and pulse width; and compensating the zero offset error of the fiber-optic gyroscope according to a zero offset increment prediction result before emission. According to the invention, the angle measurement precision of the fiber-optic gyroscope in a launching impact environment is effectively improved.

A miniaturized interferometric integrated photonic gyroscope structure with top silicon oxide, middle silicon oxide and bottom silicon oxide deposited on a silicon substrate comprises broadband optical source or a semiconductor optical amplifier with silicon nitride ring resonator wavelength filter, connected with a thin film lithium niobate or piezoelectrically actuated silicon nitride phase modulator vertically coupled with a silicon nitride waveguide spiral loop. The silicon nitride waveguide spiral loop is patterned on thin bottom oxide layer with air trenches below it and connected with a germanium detector either through photonic wire bonding or vertically integrated through reflecting mirror embedded into silicon wafer. Various methods of coupling alternative materials are described and the potential of connecting several spiral waveguides for enhanced sensitivity in a gyroscope application.

The invention relates to the field of performance testing of high-precision fiber-optic gyroscopes, and discloses an automatic testing method and system for the extinction ratio of a high-precision fiber-optic gyroscope, and the method comprises the following steps: constructing a signal light path and a reference light path, and combining the output light of the signal light path and the reference light path into a combined light signal in an orthogonal polarization state; integrally measuring the extinction ratio of the combined optical signal by using an extinction ratio tester to obtain a measured value; the control unit compares the measured value with a target value of 0dB and generates a control instruction based on a difference value; the voltage controller automatically adjusts the voltage of the integrated optical modulator in the signal light path according to the instruction, and iterative optimization is carried out through closed-loop feedback until the actually measured extinction ratio reaches a target value; and finally recording and solidifying the optimal voltage value. According to the invention, single and accurate extinction ratio overall measurement is used for replacing two times of error-prone independent optical power measurement, full-automatic closed-loop control is realized, the precision, efficiency and consistency of optical power balance are remarkably improved, and the skill requirements on operators are reduced.

According to the fiber-optic gyroscope for suppressing the relative intensity noise of the light source based on the double Y waveguides, interference signal light output by the same light source and noise polarization correlation of matched reference light are utilized, fine adjustment is carried out through the design of the two Y waveguides, so that the output intensity of the two Y waveguides is precisely consistent, polarization states are orthogonal, and the relative intensity noise of the gyroscope light source is suppressed; the precision of the gyroscope is improved; multiple polarization beam splitter assembly light paths are specially designed in a gyroscope light path, polarization state orthogonality and equal-light-intensity light splitting and light combination can be achieved, the specific use method of the gyroscope light path design is further provided, fiber-optic gyroscope homologous interference signal light and matched reference light can specifically meet the adjustment requirements, and the method is suitable for popularization and application. The light source relative intensity noise is effectively reduced, and the output signal-to-noise ratio is improved. The device is simple in design structure, low in implementation difficulty, capable of being finely adjusted, high in adaptability, good in noise suppression effect, suitable for single-axis and multi-axis fiber-optic gyroscopes and also suitable for other fiber-optic sensors with similar optical path structures.

The invention relates to a disassembly-free online self-calibration double-shaft laser gyroscope strapdown inertial navigation implementation method, which designs a modulation working mode based on double-shaft rotation, according to the design, a double-shaft rotating mechanism is additionally arranged on an inertial navigation unit, and the inertial navigation unit respectively rotates around three gyroscope sensitive shafts by utilizing an outer horizontal shaft and an inner azimuth shaft; exciting a navigation error generated by a scale factor error and an installation error of the laser gyroscope; sensitive shafts of the three accelerometers are enabled to point to the sky respectively, and navigation errors generated by scale factor errors, installation errors and zero positions of the accelerometers are excited; and then obtaining the navigation errors by taking external reference information as a benchmark, establishing an error relation model between the navigation errors and parameters needing to be calibrated, and completing estimation of each calibration parameter by adopting a Kalman filtering algorithm, so as to realize disassembly-free online self-calibration of the double-shaft laser gyroscope strapdown inertial navigation.

The invention provides a method and a system for realizing a weak measurement enhanced chip-level microcavity gyroscope. The method comprises the following steps of: 1, providing a coherent state input by a system by using a single-frequency laser; 2, the output of the single-frequency laser is switched between a first path and a second path through an optical switch, the laser beam is transmitted to the first path in the first half part of the period, and the laser beam is transmitted to the second path in the second half part of the period; 3, the light transmitted along the first path and the second path respectively passes through an optical resonant cavity to sense the rotation angular speed, and a weak value amplification effect is achieved by setting front and back selection states; and step 4, weak measurement enhanced output results transmitted along the first path and the second path are respectively received by a photoelectric detector, and the value of the rotation angular velocity is demodulated according to the obtained output results. According to the invention, the optical microcavity is used as a sensing unit of the gyroscope, the sensing performance of the integrated optical gyroscope is greatly enhanced through a weak measurement technology, and the whole set of system can realize chip-level integration.

A device for measuring a quantity representative of a population (N) of cold atoms, the cold atoms being located in a cloud of cold atoms to be analyzed, the device includes a microwave source configured to generate an incident signal at a predetermined signal frequency, a microwave guide configured to propagate the incident signal and an antenna configured to emit the incident signal to the cloud of cold atoms and its environment, the antenna and the microwave guide also being able to recover an atomic reflected signal resulting from a reflection of the incident signal by the cloud and its environment, and which propagates in the waveguide in the opposite direction to the incident signal, a splitting device coupled to the microwave guide and configured to extract at least part of the atomic reflected signal, a detector configured to detect the atomic reflected signal extracted by the splitting device, the quantity representative of the population of cold atoms (N) being obtained from a detected value of the atomic reflected signal and from a detected value of a signal reflected by the environment in the absence of the cloud, called reference reflected signal.

The present disclosure relates to integration of integrated photonics-based optical gyroscopes and fiber-based optical gyroscopes into portable apparatuses that may include compass features. Novel small-footprint modularized fully integrated photonics optical gyroscopes are used for non-critical axes. However, for at least one critical axis, a fiber-optic gyroscope can be used to provide bias stability below 0.1° / Hr, which is directly correlated to predicting positional accuracy in the centimeter range. The positional accuracy results from the compassing ability of the gyroscope (referred to as gyrocompass) to calculate direction of heading using the earth's rotation.

The invention discloses a turnout space structure parameter intelligent detection device and a method thereof, which utilize laser scanning and multi-sensor fusion technology and integrate a mechanical-electrical integrated structure, realize effective detection of turnout space structure parameters, meet the rapid and comprehensive detection requirements of common single-open turnouts, and improve the detection efficiency. The defects of low efficiency and more missed judgment of manual patrol are overcome, the detection efficiency is greatly improved, and automatic and intelligent detection equipment and technical means are provided for a railway engineering site.

The invention discloses an interference type fiber-optic gyroscope error suppression method based on adaptive phase modulation, which comprises the following steps of: modeling a closed-loop working model of an interference type fiber-optic gyroscope to obtain an open-loop transfer function and a closed-loop transfer function of the fiber-optic gyroscope; analyzing steady-state errors under slope input and acceleration input signals according to the open-loop and closed-loop transfer functions; according to the transfer function, analyzing and establishing a relationship between the modulation phase and the signal-to-noise ratio and the random walk coefficient of the fiber-optic gyroscope; according to the rotation angular acceleration of the fiber-optic gyroscope, the modulation depth of phase modulation is adaptively adjusted through the relation between the steady-state error and the modulation phase and the signal-to-noise ratio and the random walk coefficient of the fiber-optic gyroscope, so that the angular rate tracking error is inhibited, and the measurement precision is improved. When the interference type fiber-optic gyroscope is in the high maneuvering mode, the phase can be adaptively adjusted and modulated according to the input rotation angular rate, the open-loop gain is improved, and the output error is reduced, so that the overall performance of the fiber-optic inertial navigation IMU in the high maneuvering mode is improved.

The invention provides a passive laser gyroscope based on a light force induced transparency effect and a measurement method thereof, the passive laser gyroscope comprises a frequency stabilized laser light source, a signal modulation input device, a balance homodyne detection device, an annular optical resonant cavity and a signal detection and feedback device, wherein a reflection cavity mirror with a photomechanical resonance structure characteristic is integrated in the annular optical resonant cavity; according to the passive laser gyroscope, a narrow transparent window modulated by a mechanical damping rate is generated on an annular optical resonant cavity of the passive laser gyroscope by utilizing a light force induced transparency effect and a light-mechanical coupling effect, so that the quality factor of the annular optical resonant cavity is improved, and the measurement sensitivity of the passive laser gyroscope is enhanced.

The utility model discloses an optical fiber ring packaging device, which comprises a packaging cover, an optical fiber ring and a packaging base, the packaging base is provided with an annular cavity, and the optical fiber ring is accommodated in the annular cavity. The packaging cover and the packaging base are connected in a matched mode to form a magnetic shielding face. The outer side joint and the inner side joint of the packaging cover and the packaging base are welded through laser. The laser direction is perpendicular to the magnetic shielding surface. According to the utility model, when the high-precision optical fiber ring is packaged and welded, the welding seam still has an anti-magnetic shielding function, and the magnetic field performance of the optical fiber ring is improved.

The invention discloses a single-laser self-injection locking resonant optical gyroscope based on light intensity detection and a working method thereof, and belongs to the technical field of optical gyroscopes, a working light source DFB laser is connected with a first port of a circulator, and a second port of the circulator is connected with a beam splitting coupler through an isolator; two output ends of the beam splitting coupler are respectively connected with an input end of the echo wall microcavity and the phase modulator, and the phase modulator is connected with the other input end of the echo wall microcavity; a first port of the output end of the echo wall microcavity is connected with a third port of the circulator, and a second port of the output end of the echo wall microcavity is connected with the frequency locking amplifier through the photoelectric detector. According to the invention, the problems of high cost of double light sources in the self-injection locking resonant optical gyroscope and frequency drift and complex structure of beat frequency detection are solved, so that the measurement precision and economical efficiency of the gyroscope are effectively improved.

The present application relates to a fiber optic gyroscope with stress compensation. In addition to the existing fiber optic gyroscope comprising a light source, a coupler, a Y-waveguide, a fiber optic ring, a detector, and a signal processing circuit, a temperature sensor and a piezoelectric ceramic are added. The coupler is connected to the light source, the detector, and the Y-waveguide, respectively; and the signal control circuit is connected to the detector, the temperature sensor, the Y-waveguide, and the piezoelectric ceramic, respectively. Since the fiber optic ring is wound with a first optical fiber and a second optical fiber, the Y-waveguide and the fiber optic ring are connected via a first optical fiber pigtail and a second optical fiber pigtail, and the first optical fiber pigtail or the second optical fiber pigtail is also wound around the piezoelectric ceramic. During operation, the signal processing circuit controls the piezoelectric ceramic in real time to perform pressure compensation on the first optical fiber pigtail or the second optical fiber pigtail wound around the piezoelectric ceramic based on the sensitive angular velocity information and temperature information of the fiber optic gyroscope, thereby balancing the stress values ​​on both sides and thereby compensating for the zero drift of the fiber optic gyroscope caused by stress.

A compact grating-mirror magneto-optical trap (GMOT) cold atom inertial sensor head is disclosed. To make the sensor head compatible with the high vibration levels encountered in dynamic environments, the number of optical ports in the vacuum chamber is minimized and various components, including fixed optical components and a reflective grating chip, are hard mounted within the vacuum chamber. The use of the reflective grating chip reduces the number of optical ports required for cooling beams from six to one. The number of optical ports is further reduced by time multiplexing multiple beams passing through a given optical port.

The invention discloses a four-frequency differential laser gyroscope dynamic dispersion balancing method and device, and the method comprises the steps: inputting a constant current to a dispersion coil through a gain medium coil current control module, and applying a constant axial magnetic field to a gas gain medium by the dispersion coil; the Faraday coil current control module inputs controllable current to the Faraday coil, controls the axial bias magnetic field of the Faraday chamber, and changes the offset frequency amount generated when a light beam passes through the Faraday chamber, so that the offset frequency amount of the Faraday chamber is equal to the Zeeman effect offset frequency amount, and the dynamic dispersion balance of the four-frequency differential laser gyroscope is realized. In the dynamic dispersion balance process, different from the direct influence of the axial magnetic field change of the gain medium on the offset frequency of the gyroscope, the variable quantity caused by the axial bias magnetic field change of the Faraday chamber can be differentially removed in the operation process of the gyroscope, so that the influence on the final output of the gyroscope is very small, and meanwhile, the modulation on the cavity length in the operation process of the gyroscope is avoided.

The invention provides a synchronous closed-loop control method for detecting laser light intensity and frequency by a nuclear magnetic resonance gyroscope, which comprises the following steps of: firstly, detecting laser detection power fluctuation by utilizing a splitting part of a beam splitter prism, and realizing closed-loop stable control on the detection laser power by adjusting injection current of a detection laser tube; secondly, a detection power signal absorbed by the air chamber is extracted through a summation signal of the polarization balance beam splitting detection system, the signal reflects fluctuation of the detection laser frequency, and finally synchronous closed-loop stable control over the detection laser frequency is achieved by adjusting the temperature of a detection laser tube with the signal as a closed-loop feedback signal. The synchronous closed-loop stable control of the nuclear magnetic resonance gyroscope detection laser power and frequency can be realized, the nuclear magnetic resonance gyroscope output signal drift caused by the fluctuation of the detection laser power and frequency is inhibited, and the long-term stability of the gyroscope output signal is improved. By applying the technical scheme provided by the invention, the technical problem that the miniaturization requirement of the nuclear magnetic resonance gyroscope is difficult to meet in the prior art is solved.

The invention relates to a split type modularized three-axis integrated optical fiber gyroscope structure. The split type modularized three-axis integrated optical fiber gyroscope structure comprises an optical fiber gyroscope control assembly and three optical fiber gyroscope light path assemblies, the four assemblies are mutually independent in structure, are connected only through wire harnesses, can be flexibly arranged according to system-level application requirements, and are suitable for various types of system products. The three-axis integrated optical fiber gyroscope is high in component modularization, compact in layout and reasonable in material selection, and high reliability and high applicability of the three-axis integrated optical fiber gyroscope under the condition of small size and weight are realized. The heating components are all installed in the optical fiber gyroscope control assembly, complete isolation between the heating device and a polarization maintaining light path is achieved, the influence of temperature change of the heating device on the light path is avoided, and the starting characteristic and the temperature performance of the gyroscope are improved. Materials are preferably selected in the optical path assembly of the optical fiber gyroscope, the structure is refined, the characteristics of reducing the weight and guaranteeing high strength and high rigidity are considered, optical fibers are free of suspension in fiber walking, the fiber walking radius is maximized, the mechanical environment adaptability of the gyroscope is high, and the long-term stability of the precision of the gyroscope is guaranteed.

The invention relates to an optical fiber ring module with high magnetic shielding performance and a manufacturing method thereof, and solves the technical problem of limited magnetic shielding performance in the prior art. The shielding device comprises a base, a shielding framework sleeving the base and a shielding bottom cover, an optical fiber ring is arranged in the shielding framework; a Y waveguide, a coupler and a temperature sensor are mounted on the base; a first-layer upper shielding cover and a first-layer lower shielding cover are respectively arranged on the outer layer to realize first-layer full magnetic shielding; a second-layer upper shielding cover, a second-layer shielding cylinder and a second-layer lower shielding cover are correspondingly connected to realize second-layer full magnetic shielding; and a third-layer shielding cover is arranged, and the third-layer shielding cover and the third-layer shielding sleeve are correspondingly connected to realize third-layer full-magnetic shielding. Wherein the first magnetic shielding layer and the third magnetic shielding layer are made of magnetic conductive materials so as to shield interference of a low-frequency magnetic field, the middle second magnetic shielding layer is made of conductive materials so as to shield interference of a high-frequency magnetic field, and the magnetic shielding performance is improved through three-layer full magnetic shielding coating.

A mower includes a chassis, a driveline coupled to the chassis and configured to drive a tractive element to propel the mower, a cutting unit coupled to the chassis, the cutting unit including a housing and a cutting element rotatably coupled to the housing, and a controller operatively coupled to the driveline. The controller is configured to identify a desired path for the mower, receive location data indicating a current path being traveled by the mower, determine that the current path of the mower deviates from the desired path, and control the driveline to oppose the deviation of the current path from the desired path.