On-line estimation of installation error and north-seeking error compensation method of modulated north-finder in tilted state

Abstract

The invention relates to an installation error online estimation and north-seeking error compensation method for modulating a north seeker under an inclined state. The installation error online estimation and north-seeking error compensation method is characterized by comprising the following steps: step 1, establishing a geographic coordinate system, a carrier coordinate system, a platform coordinate system, a gyro coordinate system and a conversion relation of the four systems; step 2, establishing an output model under the inclined state when a rotary platform rotates along the own vertical central shaft at a constant speed and a gyro has an installation error angle; step 3, establishing an output model under the inclined state when the rotary platform rotates along the own vertical central shaft at the constant speed and an accelerometer has the installation error; step 4, processing an output signal of the gyro and the accelerometer to obtain an inclined angle of a carrier; step 5, carrying out online estimation on the installation error angle according to results obtained by processing the gyro and the accelerometer in the step 4; and step 6, estimating a north-seeking error according to the signal of the gyro processed in the step 5 and the inclined angle of the carrier obtained in the step 4,and revising a course angle roughly-estimated angle to obtain an accurate course angle and finish the north seeking of the carrier.

Description

technical field [0001] The invention relates to a method for on-line estimation of the installation error of a modulation north-finder and compensation for the north-seeking error in an inclined state. Background technique [0002] In the practice of human social life, geographical orientation is indispensable information. North-finding is to find out the bearing relationship of the carrier relative to the north of the earth, that is, to determine the heading angle of the carrier. Strapdown north-seeking is also called analytic north-seeking. It utilizes the gyroscope to be directly sensitive to the angular velocity component of the earth’s rotation. It has the advantages of quick response and simple structure. It can also directly use advanced optical gyroscopes as ideal north-seeking inertial components. The north-finding methods used in strapdown north-seeking mainly include static north-seeking and dynamic north-seeking. Static north-finding methods include single-posit...

AI Technical Summary

Problems solved by technology

[0004] In practical engineering applications, with the change of external environmental factors such as humidity and temperature when the north finder is working, the mechanical connection between the gyro and the turntable will be deformed due to the change of force, resulting in a gap between the gyro coordinate system and the platform coordinate system. There is an installation error angle between them, and the size of the error angle is closely related to external interference factors, which cannot be described by a definite change rule.

At present, there is no specific method to overcome the north-finding error caused by the installation error angle, which seriously restricts the north-finding accuracy in practical applications

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