28 results about "Bearing (navigation)" patented technology

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 belongs to the technical field of positioning navigation, and discloses an initial course alignment method and device based on geometric constraint type filtering, and the method comprises the steps: calculating a magnetic course angle and estimating the GNSS driving distance and orientation according to received GNSS original observation data, earth magnetic field information, and accelerometer data and gyroscope data obtained based on an IMU array; based on an unscented Kalman filtering algorithm under a Gaussian progressive framework, correcting accelerometer data in combination with geometric constraints, and identifying an IMU with a fault in the IMU array for isolation to obtain filtered accelerometer data and gyroscope data; calculating to obtain a GNSS-IMU course angle by combining the filtered accelerometer data and gyroscope data and the GNSS driving distance and direction; and according to the loss duration of the GNSS original observation data, synthesizing the magnetic course angle and the GNSS-IMU course angle to obtain a final initial course angle. The initial alignment time of the integrated navigation system is effectively shortened, and the robustness of the system is enhanced.

The utility model relates to the technical field of foundation navigation, and discloses an anti-interference device for foundation navigation, which comprises an anti-interference device and a fixed base, a foundation navigator body is mounted on the surface of the top end of the fixed base, a buffer device is mounted on the surface of the top end of the fixed base, and an antenna is mounted on the surface of the top end of the buffer device. The fixed base is in threaded connection with the lower end of the anti-interference device. According to the anti-interference device for foundation navigation, the connecting piece, the metal block, the anti-interference filter and the connecting frame are arranged, the connecting piece is inserted into the metal block, and the connecting piece and the connecting frame can clamp and fix the anti-interference filter, so that the connecting piece is quickly and conveniently separated from the metal block, and the anti-interference filter is quickly and conveniently disassembled; the insertion frame drives the bearing frame to move outwards, so that the insertion frame and the connecting frame are fixed through threads, the anti-interference filter can be clamped and fixed, and the safety of the anti-interference filter can be protected.

The present invention relates to the technical field of ship navigation operations, and provides a three-dimensional route monitoring method and system. The method includes determining the current segment based on the horizontal and vertical distances between two waypoints in the segment; calculating the horizontal deviation distance and the intersection point of the underwater vehicle and the current segment, and calculating the depth deviation distance and the three-dimensional deviation distance based on the intersection point; detecting whether there is an obstacle hazard using a fan-shaped detection azimuth interval method; obtaining the current water depth based on grid terrain data or nautical chart data, and calculating the true water depth based on tidal data and the current water depth; calculating the depth of the underwater vehicle from the water bottom based on the true water depth, and detecting whether there is a depth hazard based on the depth from the water bottom. The present invention solves the problem that traditional two-dimensional segment judgment cannot adapt to the three-dimensional underwater environment. It enables the vehicle to accurately identify the current segment even in complex sea conditions, grasp the true water depth of the current position in real time, effectively avoid dangers such as collisions with submarine mountains, and improve the safety of deep-sea navigation.

The present application belongs to the technical field of inertial navigation, and discloses a kind of modulation type inertial measurement unit's inertial device health state real-time monitoring method, suitable for aviation navigation, marine navigation and other application scenarios.The present application cooperates with the relative output information of two sets of inertial navigation system to construct constraint observation, establishes a joint error state adaptive filter as a state monitoring filter, establishes a real-time state monitoring criterion based on the estimated output of the filter, clearly defines the diagnostic threshold and performs health state monitoring, and proposes a bearing gyro drift change quantity fitting method to realize abnormal state monitoring of the bearing gyro.The inertial device health state monitoring method proposed by the present application does not require accurate reference information assistance, providing a reliable guarantee for the safety and reliability of long-time navigation in GNSS denial environment.

The present invention discloses a self-alignment method for an inertial navigation system that combines multiple rotations and stops. Specifically, the system is placed on a stable platform, recorded as the first position, with the x, y, and z axes basically pointing to the east, north, and sky, and remains stationary at the initial first position for t1 time; the internal motor rotates 180° in the forward direction to the second position, consuming time t2, and then remains stationary for t3 time; the internal motor rotates 180° in the forward direction to the first position again, consuming time t4, and then remains stationary for t5 time; the internal motor rotates 180° in the reverse direction to the second position, consuming time t6, and then remains stationary for t7 time; the internal motor rotates 180° in the reverse direction to the first position, consuming time t8; repeat the above process n times, establish an alignment filter model, select the ratio of rotation and stop time and rotation angular velocity, and improve the azimuth alignment accuracy. The method provided by the present invention can effectively improve the azimuth alignment accuracy.

The application relates to an inertial navigation comprehensive correction method based on a normal vector position model, which comprises the following steps: receiving a real-time rotation angular velocity vector and a specific force vector, binding initial navigation parameters, obtaining an initial normal vector position vector, an initial quaternion position vector and an initial direction cosine matrix, obtaining an initial velocity and an initial attitude matrix; obtaining a current velocity, a current attitude matrix and a current quaternion position vector; obtaining a current damping velocity and a current damping quaternion position vector, calculating a normal vector integral term; judging whether comprehensive correction is needed, if yes, adjusting an external reference position based on an observation number; if the observation number is greater than 1, adjusting a horizontal position to the external reference position, obtaining a drift angle and an azimuth gyro drift, correcting an attitude matrix output according to the drift angle, and using the azimuth gyro drift for navigation calculation; recording a time of successful observation and setting the normal vector integral term to zero; repeating the foregoing steps until navigation is completed.

The application discloses a kind of methods for measuring damping velocity based on additional accelerometer of inertial navigation system, it is related to the technical field of inertial navigation system application.The method comprises: obtaining the first road Kalman filter rough alignment state variable of inertial navigation system, and first road Kalman filter fine alignment state data;According to the first road Kalman filter rough alignment state variable, and first road Kalman filter fine alignment state data, calculate the first road navigation solution correction parameter;According to the first road navigation solution correction parameter, determine current orientation cosine matrix, and obtain the acceleration measurement value of accelerometer output;In the second road navigation solution loop, according to the acceleration measurement value, the current orientation cosine matrix and accelerometer component speed measurement equation, calculate the damping velocity of ship.The technical scheme of the embodiment of the application can accurately calculate the damping velocity of ship under the premise of low hardware cost, and provide data basis for ship navigation.

The invention discloses a positioning orientation and gravity measurement method based on biaxial strapdown inertial navigation. The biaxial strapdown inertial navigation comprises an inertial measurement device, an outer ring used for enabling the inertial measurement device to rotate around a pitch axis, and an inner ring used for enabling the inertial measurement device to rotate around an azimuth axis; when no gravity measurement instruction is input, the rotation angle of the outer ring is kept at 0 degree, and the inner ring circularly rotates in a reciprocating manner according to a set rule so as to eliminate course angle errors measured by the inertial measurement device; when a gravity measurement instruction is input, the biaxial strapdown inertial navigation system is controlled to be converted into a gravity measurement mode from a positioning and orientation mode, an outer ring is controlled to rotate by-90 degrees and + 90 degrees in the gravity measurement mode, gravity data are measured respectively, and then a gravity measurement result is obtained; and after a gravity measurement result is obtained, exiting the gravity measurement mode and switching to a positioning and orientation mode. According to the invention, integration of positioning orientation and gravity measurement is realized, the system complexity is reduced, and the measurement precision and stability are improved.

The present application relates to the technical field of azimuth measurement, in particular to a method for measuring the azimuth and distance between a ship and other objects, comprising the following steps: obtaining latitude, longitude, time and heading and checking the matching, combining echo and azimuth line to screen superimposed heading, matching distance mark circle and range screening, fusing direction distance correlation screening, checking consistency and removing abnormalities. In the present application, by establishing time correlation and consistency constraints of multi-source navigation elements, latitude, longitude and heading are formed into a unified reference and abnormality is removed, the stability of the measurement reference is improved, deviation identification and screening are carried out in combination with the relationship between echo direction and angle, the consistent performance of direction determination is enhanced, distance verification is carried out using spatial relationship and range information and time matching constraints are introduced, the influence of interference is reduced, a unified relationship is constructed in the fusion stage of azimuth and distance and consistency comparison is carried out, the measurement stability and data fusion reliability in differentiating environment are improved through sequential continuity identification and abnormality filtering.

The invention relates to the technical field of underwater gravity measurement, and discloses a leveling mechanism, a gravimeter and an underwater gravity dynamic measurement system.The leveling mechanism comprises a bearing frame, a first frame, a second frame, a first electric executing mechanism and a second electric executing mechanism, the first frame can rotate around a first axis; the second frame is movably mounted in the first frame and can rotate around a second axis, and the first axis and the second axis are orthogonal; the first electric actuating mechanism is used for adjusting the roll angle of the first frame; the second electric actuating mechanism is used for adjusting the pitch angle of the second frame. By means of the design, compared with a single-axis compensation system, pitching and rolling disturbance in the navigation process of the AUV or the ROV can be offset at the same time, so that the horizontal keeping capacity of the underwater gravity dynamic measurement system in the three-dimensional dynamic environment is improved, measurement errors caused by multi-axis attitude coupling can be reduced, and the gravity measurement precision is improved.

The application relates to a high-precision alignment method of airborne inertial navigation, which comprises the following steps: step 1, selecting a coarse alignment mode according to an initial alignment scene selected by a user; step 2, performing inertial navigation coarse alignment according to the coarse alignment mode selected in step 1; step 3, after the inertial navigation coarse alignment in step 2 is completed, obtaining a rough initial attitude angle and a position cosine matrix, and then performing fine alignment; and step 4, when the airplane maneuvering is completed, the inertial navigation completes the fine alignment process by using a Kalman filtering algorithm, the attitude angle error estimated by the Kalman filtering is used to correct the navigation solution attitude angle of the strapdown inertial navigation itself, after the fine alignment is completed, the inertial navigation enters a navigation state, and the corrected attitude and speed information are output, and then the initial alignment process is completed. The application can realize high-precision alignment and does not need the assistance of high-precision master inertial navigation or high-precision satellite navigation RTK information.

The invention provides an unmanned vehicle attitude and position calculation method based on an integrated navigation technology, and the method comprises the following steps: S1, determining initialization parameters based on inertial navigation, magnetometer and Beidou navigation data, and outputting the initialization parameters, the initialization parameters including IMU initial zero offset, a rotation matrix of a vehicle body and a navigation coordinate system, and a true north navigation direction angle; s2, collecting asynchronous data of the sensor through a software polling mechanism and buffer management; the sensor comprises an IMU (Inertial Measurement Unit), a magnetometer and a Beidou navigator; and S3, after motion constraint and filtering preprocessing are carried out on the asynchronous data of the sensor output in the S2, data fusion is realized through a prediction process and a correction process of an ESKF algorithm in combination with initialization parameters, and an optimal pose estimation result of the unmanned vehicle pose is output. According to the invention, the data of the IMU, the magnetometer and the Beidou navigation module are fused, the functions of high-frequency motion sensing, azimuth calibration, absolute positioning and the like are realized, and the limitation of a single navigation means is solved through ESKF algorithm fusion.

The embodiment of the invention provides a navigation method, device and equipment, a readable storage medium and a product. The method comprises the following steps: acquiring a first object in a visible range of a first position; determining a first navigation instruction based on the first position and the first object; the first navigation instruction comprises associated information of the first object and first azimuth information, and the first azimuth information is generated based on a position relationship between the first position and the first object; and outputting the first navigation instruction. The first navigation instruction is combined with the associated information, the first position and the first azimuth information of the first object, so that the navigation object can determine the current travel route more visually, and travel is faster and more accurate.

The invention discloses a single-axis rotation inertial navigation system and method for monitoring gyroscope on-line compensation azimuth drift, and belongs to the technical field of inertial navigation, the system comprises a main IMU, a single-axis rotation mechanism, a monitoring assembly and a data signal processing module; rotating shafts at the upper end and the lower end of a main IMU are installed in rolling bearings at the top and the bottom of an outer shell, an orientation torque motor shaft in a single-shaft rotating mechanism and the rotating shafts at the two ends of the main IMU are coaxially installed, and rotating shafts at the left end and the right end of a rotating table body in a monitoring assembly are installed in rolling bearings in the main IMU in the horizontal direction. The data signal processing module is distributed on the side surface of the main IMU and in a top electronic cabin of the outer shell; the monitoring assembly comprises a monitoring gyroscope, and the main IMU comprises an orientation gyroscope. According to the method, the azimuth gyroscopic drift is equivalent to a mean value in a monitoring period by using a segmented mean value algorithm, so that the on-line estimation compensation of the azimuth gyroscopic drift can be realized, and the autonomy and the concealment of the inertial navigation system during the working period are ensured.

The invention discloses an underwater follow-up rotating towed body for integrated navigation. Comprising an external follow-up housing, stabilizing wings, a fixed frame, a rolling bearing and a combined navigation assembly, the outer surface of the external follow-up housing is connected with a stabilizing wing; a combined navigation assembly and a fixed frame which are coaxially arranged from inside to outside are arranged in the external follow-up housing, and the upper end and the lower end of the combined navigation assembly are rotationally connected with the fixed frame through rolling bearings respectively; the fixed frame is fixedly connected with the external follow-up housing, and the combined navigation assembly is electrically connected with the outside; when the external follow-up housing is placed underwater, the external follow-up housing freely rotates around the central shaft under the action of hydrodynamic force, and the rotating motion of the external follow-up housing is decoupled by the rolling bearing, so that the external follow-up housing and the fixed frame can rotate relative to the combined navigation assembly, and the combined navigation assembly is kept in a stable state. The structure is ingenious, the problem that the navigation precision of a traditional towed body is greatly disturbed by fluid is effectively solved, and the reliability and stability of underwater long-endurance and high-precision navigation are remarkably improved.

The invention discloses a method for measuring a damping speed of an inertial navigation system based on an additional accelerometer, and relates to the technical field of inertial navigation system application. The method comprises the following steps: acquiring a first-path Kalman filtering coarse alignment state variable and first-path Kalman filtering fine alignment state data of the inertial navigation system; according to the first-path Kalman filtering coarse alignment state variable and the first-path Kalman filtering fine alignment state data, calculating a first-path navigation calculation correction parameter; determining a current azimuth cosine matrix according to the first path navigation calculation correction parameter, and obtaining an acceleration measurement value output by an accelerometer; and calculating the damping speed of the ship according to the acceleration measurement value, the current azimuth cosine matrix and an accelerometer assembly speed measurement equation in a second path of navigation calculation loop. According to the technical scheme provided by the embodiment of the invention, the damping speed of the ship can be accurately calculated on the premise of low hardware cost, and a data basis is provided for ship navigation.

The invention belongs to the technical field of inertia, and provides an azimuth misalignment angle estimation method based on adaptive filtering under a vibration condition aiming at the problem that the azimuth accuracy cannot be kept for a long time under the vibration condition after a strapdown inertial navigation system completes alignment in the prior art. Acquiring a navigation speed output by the strapdown inertial navigation system; s2, extracting the navigation speed by using a recursive least square method with a forgetting factor to obtain a speed error; s3, constructing a state equation and a measurement equation of azimuth misalignment angle estimation; and S4, based on the state equation and the measurement equation, obtaining an estimated value of an estimated state through recursive calculation by an adaptive filtering algorithm, namely obtaining an estimated value of the azimuth misalignment angle. The method has the advantages of being good in environmental adaptability, high in anti-interference performance and high in precision, and has wide application prospects in the military application field.

This invention belongs to the field of inertial navigation technology and relates to a high-precision calibration method for residual drift in a rotating modulation inertial navigation system, suitable for long-endurance flight environments. This invention establishes a mathematical model of the latitude and longitude navigation error of the rotating inertial navigation system's geographic system, along with the geographic system's azimuth residual drift, northward residual drift, and azimuth mathematical platform error angle. Through the design of long-endurance navigation experiments at eight positions with azimuth angles of 45° intervals from 0 to 360°, accurate identification of azimuth and northward residual drift, as well as alignment heading errors, is achieved at different azimuths. This invention offers high accuracy in residual drift identification, significantly improves long-endurance navigation performance, is highly autonomous, and is easy to implement.

The invention discloses a navigation light inspection method and device, electronic equipment and a storage medium, and relates to the ship signal light inspection technology, and the method comprises the steps: obtaining the ship position information and the observation position information of a navigation light to be detected; the observation position information is obtained based on the appearance position or disappearance position of the navigation light to be detected detected by the unmanned aerial vehicle equipment; determining the azimuth angle of the unmanned aerial vehicle equipment relative to the ship compass system according to the ship position information and the observation position information; and obtaining a deviation angle of the ship compass system, determining a test angle of the navigation light to be tested according to the deviation angle and the azimuth angle, and checking whether the installation of the navigation light to be tested is qualified or not according to the test angle. According to the method, the azimuth angle required by calculation can be obtained by operating the unmanned aerial vehicle, and the test angle of the navigation light to be detected can be calculated by combining the deviation angle of the ship compass system, so that the detection process is simplified, and the beneficial effects of improving the detection efficiency and reducing the detection cost are achieved.

This invention relates to a ship resonant icebreaking device, comprising a base, a load-bearing rod, a load-bearing hydraulic rod, an impact wheel, a hatch, a hatch linkage, and a reduction motor. The base is fixed to the ship's deck, and the load-bearing rod is hinged to the base. Both sides of the load-bearing rod are connected to the base via front and rear load-bearing hydraulic rods, respectively. The front end of the load-bearing rod is connected to the impact wheel located at the hatch. The hatch is connected to the reduction motor via a hatch linkage. Based on the natural frequency f1 of the ice layer in the navigation area, the ship's speed is adjusted to achieve an impact frequency f1 generated by the impact wheel. n The impact wheel operates at the same natural frequency f1 as the ice layer, achieving a resonant icebreaking effect. Under the same displacement conditions, this invention can provide a greater impact force to the ice layer. During icebreaking operations, no additional power equipment is required; the impact wheel rotates using the ship's forward speed, thus completing the icebreaking operation with lower energy consumption.

The application discloses a dynamic attitude navigation error evaluation method and system of a rotating inertia system, which comprises the following steps: synchronously acquiring a position turntable ring frame angle signal and an inertia output signal of the rotating inertia system; obtaining a shell attitude matrix of the rotating inertia system relative to a navigation system according to a frame angle signal and a gyroscope output signal of the rotating inertia system by using a navigation solution method; obtaining a reference attitude matrix of an inertia system mounting surface relative to the navigation system according to a mounting direction of the position turntable and the ring frame angle signal; performing a direction cosine method solution according to the reference attitude matrix signals of the inertia system shell and the mounting surface to obtain an attitude error matrix; and obtaining an inertia system attitude navigation error angle according to the relationship between the attitude error angle and the direction cosine matrix. The application can be applied to dynamic attitude navigation precision evaluation of the rotating inertia system and has high applicability and accuracy.

The application relates to a high-precision initial alignment method, which comprises the following steps: a transfer alignment step: providing a main inertial navigation system and a sub-inertial navigation system, rotating 90 degrees around a horizontal axis to be erected, obtaining a first attitude matrix of the sub-inertial navigation system after the erection is completed through a transfer alignment algorithm, and completing azimuth fine alignment; a rotation modulation step: rotating the sub-inertial navigation system 180 degrees around the skyward axis to a symmetrical position and then rotating-180 degrees back to the original position for rotation modulation at the in-place position of the transfer alignment step, taking the first attitude matrix as an initial attitude, and obtaining a second attitude matrix of the sub-inertial navigation system to complete horizontal attitude fine alignment; and a fusion step: fusing an azimuth result of the first attitude matrix and a horizontal attitude result of the second attitude matrix to obtain a final attitude matrix to complete initial alignment. The application provides a high-precision initial alignment method which effectively combines the characteristics of rotation modulation alignment and transfer alignment and improves the initial alignment precision.

The invention discloses a method for realizing ship bow and stern vectors by a Beidou high-precision positioning technology, which comprises the following steps of: acquiring coordinates at the bow and stern ends of a ship in real time through a Beidou No.3 high-precision positioning module, calculating an included angle between the bow and stern directions and the true north, and decomposing the central point speed of the ship into forward and transverse speeds; and finally, bow and stern directions and velocity vectors are displayed on the electronic chart. According to the method, high-precision bow and stern azimuth measurement can be provided, the error range is + / -0.0015-0.006 degrees, the ship navigation situation is visually presented, the driving safety and efficiency are improved, and the method is suitable for berthing, narrow navigation channels and other scenes.

The invention relates to the technical field of ship navigation operation, and provides a three-dimensional route monitoring method and system, and the method comprises the steps: determining a current route segment according to the horizontal distance and the vertical distance of two route points of the route segment; calculating a horizontal yaw distance and an intersection point of the underwater vehicle and the current leg, and calculating a depth yaw distance and a three-dimensional yaw distance according to the intersection point; detecting whether an obstacle danger exists or not through a fan-shaped azimuth interval detection method; obtaining the current water depth according to the grid topographic data or the sea chart data, and calculating the real water depth according to the tide data and the current water depth; calculating the depth from the underwater vehicle to the water bottom according to the real water depth, and detecting whether depth danger exists or not according to the depth from the water bottom. The problem that traditional two-dimensional leg judgment cannot adapt to the underwater three-dimensional environment is solved, the aircraft can still accurately recognize the current leg under the complex sea condition, the real water depth of the current position is mastered in real time, the danger of colliding with the seabed mountain and the like is effectively avoided, and the safety of deep sea navigation is improved.

The invention discloses a method for calibrating main parameters of an optical strapdown inertial navigation system, which comprises the following steps: mounting an inertial navigation component on a double-shaft turntable, and carrying out multi-direction reference adjustment on the position of the turntable; adjusting a machine body shaft to a WSU direction, rotating a rotary table azimuth shaft by 180 degrees after rotating a navigation state for 20 seconds, and calculating and correcting accelerometer zero constant values of an X axis and a Y axis; adjusting the body shaft to the DES direction, rotating the azimuth axis of the turntable around the W direction by 180 degrees after rotating the navigation state for 20 seconds, calculating the zero constant value of the accelerometer of the Z axis and correcting the zero constant value; adjusting an airframe shaft to a WSU direction, calculating gyroscopic drift values of a Y axis and a Z axis, adjusting the airframe shaft to an NWU direction, calculating a gyroscopic drift value of an X axis, and correcting a gyroscopic scale coefficient of a corresponding axial direction; and adjusting the environment temperature of the rotary table to a preset range, calculating gyroscopic drift values, accelerometer zero correction values and meter scale coefficient correction values corresponding to the X axis, the Y axis and the Z axis, and performing fitting compensation so as to ensure that the system can output high-precision parameter information.

The invention provides a ship dynamic window local path planning method fused with navigation rules, and belongs to the technical field of intelligent path planning. The method mainly comprises the steps of constructing a kinematic model of a ship; speed sampling is carried out, sampling speeds are screened, and an effective speed combination without collision risks is reserved; based on a kinematics model, motion simulation is carried out on the screened effective speed combination, and a plurality of simulation paths are generated; a situation judgment function is constructed, and the encounter situation is judged through the relative orientation and the course difference value; a risk function is constructed, the risk degree between the ship and the obstacle is judged, and the encounter situation is locked; and constructing an evaluation function in a dynamic window method, obtaining scoring results of the simulation paths, comparing the scoring results of all the simulation paths, and selecting a ship driving path of the next time step. The method has high efficiency, stability and accuracy in processing complex dynamic meeting scenes, and can provide reliable path planning support for autonomous navigation safety and intelligent decision making of ships.

The utility model discloses a gyro difference measuring device, which is characterized in that an optical azimuth instrument is placed on a gimbal mechanism, and a rotating shaft of the optical azimuth instrument is connected with a rotating shaft of a rotary encoder, so that when the optical azimuth instrument is rotated to enable a collimation line of the optical azimuth instrument to be aligned with the center of the sun, the rotary encoder can be used for detecting the ship side angle of the sun relative to a ship; and then the computer processing unit can quickly calculate the gyro difference according to the broadside angle obtained from the rotary encoder, the azimuth of the sun gyro obtained from the gyrocompass and the navigation data obtained from the satellite navigation equipment, so that the calculation precision of the gyro difference is effectively improved.