Optical fiber strapdown inertial navigation double-shaft rotation modulation method and double-shaft rotation mechanism

Method for error suppression of inertial concretionary coarse alignment of strapdown inertial navigation system

The invention provides an SINS (Strapdown Inertial Navigation System) error inhibiting method based on a biaxial rotation scheme. A global positioning system (GPS) is used for determining the parameters of the initial position of a carrier, and the parameters are input into a navigation computer; after preheating preparation, an SINS collects the data output by a fiber optic gyroscope and a quartz accelerometer and processes the data; primarily determining the attitude information of an inertial measurement unit (IMU) at the time according to the relationship between the output of the accelerometer and acceleration of gravity and the relationship between the output of the gyroscope and the rotational angular velocity of the earth so as to complete the initial alignment of the system; the IMU continuously rotates around the azimuth axis and the pitch axis; and the data generated by the fiber optic gyroscope and the quartz accelerometer after the rotation of the IMU is converted under a navigation coordinate system to get the modulation manner with deviated constants of inertia instruments. According to the invention, the SINS error inhibiting method based on a biaxial rotation scheme can be used for modulating the drift of the gyroscope in three directions and the zero offset of the accelerometer in the horizontal direction so as to improve the positioning precision of navigation.

SINS error inhibiting method based on biaxial rotation scheme

Rotating method of modulation type inertial navigation system with double-axis rotating continuously

A transposition method of a double-shaft rotating type strapdown inertial navigation system for a ship belongs to the technical field of inertial navigation. The system comprises an inertial sensitive unit, a monitoring unit with a computer and a double-shaft rotating unit. The inertial sensitive unit is installed on the double-shaft rotating unit, and a double-shaft rotating unit inner shaft is parallel to the Zs axis of a coordinate system XsYsZs of the inertial sensitive unit. The transposition method of the system is that the inner shaft and an outer shaft of the double-shaft rotating unit are cyclically controlled to rotate in cycles. The transposition method of the double-shaft rotating type strapdown inertial navigation system for the ship has the advantages of being simple in step, solving the problem that the traditional double-shaft transposition scheme cannot compensate scale factor errors and coupling errors of earth rotation, and effectively improving long-endurance navigation accuracy of the strapdown inertial navigation system for the ship.

Transposition method of double-shaft rotating type strapdown inertial navigation system for ship

The invention belongs to the technical field of modulation of a strapdown inertial navigation system and relates to a biaxial rotation modulation method of the strapdown inertial navigation system which aims at reducing the complexity and realizing the rate bias without a high angular acceleration reversing mechanism. The biaxial rotation modulation method comprises six steps of setting a coordinate system, mounting a gyroscope and an accelerometer, mounting an inertial measurement unit, carrying out biaxial rotation modulation, carrying out navigation calculation of the inertial measurement unit and carrying out demodulation and calculation of data on the strapdown inertial navigation system. The biaxial rotation modulation method adopts the biaxial rotation module and can realize the modulation of errors of an inertia device in the strapdown inertial navigation system and improve the navigation precision of the strapdown inertial navigation system. The biaxial rotation modulation method does not need the high angular acceleration reversing mechanism for the strapdown inertial navigation system using the laser gyroscope, thereby reducing the implementation complexity of the system and further reducing the implementation cost of the system.

Pengcheng Cui

Papers

Biaxial rotation modulation method of strapdown inertial navigation system