Electromagnetism log auxiliary marine gyrocompass action alignment method

Abstract

The invention discloses an electromagnetism log auxiliary marine gyrocompass action alignment method which comprises the following steps: feeding north orientation acceleration input and a north orientation alignment loop feedback quantity into a first comparator, feeding into a second comparator after an integration procedure, adding an initial speed into the second comparator, reducing a reference speed, after a modification procedure, dividing into a north orientation alignment loop and a direction alignment loop, outputting a south orientation misalignment angle at the north orientation alignment loop, and outputting a direction misalignment angle at the direction alignment loop. As the mechanical speed of a ship is tracked by using an electromagnetism log, and errors of earth rotational angular speeds converted into a navigation coordinate system can be eliminated through acceleration measurement compensation, the purpose of action alignment of a marine strapdown inertial navigation system can be achieved, the mechanical properties of carriers can be greatly improved, and the method is a feasible and effective action initial alignment method.

Description

technical field [0001] The invention mainly relates to gyro navigation, in particular to a method for aligning a marine gyro compass assisted by an electromagnetic log. Background technique [0002] Strapdown inertial navigation during-travel initial alignment refers to the technology in which the carrier completes the initial alignment of the inertial navigation system during the motion process. Therefore, it is a kind of initial alignment technology of the moving base. The initial alignment technology of inertial navigation has immeasurable significance and role in enhancing the carrier's maneuverability and quick response ability. [0003] Different from the initial alignment environment of the traditional static base, on the one hand, when the carrier is moving, the position, velocity, acceleration and angular velocity of the carrier are constantly changing, which will have an impact on the initial alignment; on the other hand, the linear motion will The parameters such...

AI Technical Summary

Problems solved by technology

[0003] Different from the initial alignment environment of the traditional static base, on the one hand, when the carrier is moving, the position, velocity, acceleration and angular velocity of the carrier are constantly changing, which will have an impact on the initial alignment; on the other hand, the linear motion will The parameters such as acceleration to the ground and Gothic acceleration in the basic equation of inertial navigation change all the time, so the accurate information of the acceleration of gravity cannot be measured by the output data of the accelerometer in the state of motion; the vibration of the carrier under the state of motion makes the interference angular velocity have a wide range Frequency band, the signal-to-noise ratio of the output signal of the gyroscope is low, and the useful information of the alignment of the earth's rotation angular velocity cannot be extracted from the output data of the gyroscope

[0004] Therefore, the traditional compass alignment method is not suitable for on-the-go alignment. Under the condition of carrier motion, it cannot simply rely on the direct measurement information of the gyroscope and accelerometer for initial alignment.

Moreover, the existing acceleration compensation method uses the differential of the speed of the electromagnetic log

Due to the low sampling frequency and the existence of integral errors, this method is not suitable for high-precision strapdown inertial navigation systems

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