Optical fiber gyroscope strap-down inertial navigation system initial posture determination method

Abstract

The invention discloses a determined method for an initial gesture on the basis of Doppler optical fiber gyro strapdown inertial navigation system, which comprises continuously collecting data which is output by an optical fiber gyro and a quartz flexible accelerometer after being preheated, processing the data of the gyroscope and the accelerometer which are collected, finishing a rough alignment of the strapdown inertial navigation system, entering into an extractive alignment after the rough alignment is finished, establishing a dynamic base error equation of a marine strapdown inertial navigation system, employing an optimal control filtering theory to design an electric filter, and doing a filtering estimation, extracting information of ship hull gesture misalignment angle to correct the ship hull gesture when a combined extractive alignment is finished, finishing extractive initial alignment, simultaneously obtaining shift estimated value of the gyroscope, and realizing a drift course of the initial alignment. The method of the invention can realize accurate estimation to a zero drift of the optical fiber gyro when the requirement of accuracy and rapidity is guaranteed.

Description

(1) Technical field [0001] The present invention relates to an initial alignment technology of a strapdown inertial navigation system, in particular to a combined initial alignment based on a marine optical fiber gyro strapdown inertial navigation system and another navigation system that can independently and accurately provide ship speed information standard method. (2) Background technology [0002] The initial alignment error is one of the main error sources of the inertial navigation system. The impact of the initial alignment error on the system error is not only manifested in the attitude index, but also in the acquisition of velocity and position information. Alignment accuracy directly affects navigation accuracy. Therefore, the initial alignment process must first be completed before normal navigation. [0003] Strapdown inertial navigation is a relatively popular technology in navigation technology now. Because of its low cost, it has been favored by more and mo...

AI Technical Summary

Problems solved by technology

However, this ordinary Kalman filtering method also has defects: when there are many system state variables, the calculation of the filter estimation algorithm is very large, especially in the case of augmented vectors, each additional state variable will make The amount of calculation is greatly increased, which is not conducive to the requirement of rapid initial alignment; in the process of estimating inertial device errors (mainly optical fiber gyro drift measurement), due to the long estimation time of azimuth gyro drift, it is necessary to accurately measure The estimation time must be greatly increased. At this time, the Kalman filter becomes unstable or even begins to diverge, resulting in the failure of horizontal drift measurement and the attitude angle also begins to diverge.

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