Single-axis rotary strapdown inertial navigation system calibration method based on optimization method

Abstract

The invention discloses a single-axis rotary strapdown inertial navigation system calibration method based on an optimization method; the calibration method comprises the following steps that firstly,a single-axis rotary strapdown inertial navigation system is installed on a double-axis rotary table by utilizing a tool, a system is powered on, a transposition mechanism is reset and closed, and after the temperature of the system is stable, the rotary table is used for enabling the system to sequentially turn to 18 positions; then the double-shaft rotary table is used to be matched with the transposition mechanism to carry out 9-group rate experiments, optimizing and estimating are carried out on the data by utilizing a nonlinear optimization method to obtain 18 error parameters; and finally, the system is installed on a three-axis rotary table, three position experiments and three groups of rate experiments are carried out, and an orthogonal coordinate system of an accelerometer and agyroscope is calibrated to a three-axis rotary table coordinate system. The calibration method disclosed by the invention has the advantages of automation calibration and no dependence on the precision of the rotary table, and can realize calibration of the system before delivery and re-calibration of the system after delivery for a long time.

Description

technical field [0001] The invention relates to the technical field of inertial navigation, in particular to a method for calibrating a single-axis rotation strapdown inertial navigation system based on an optimization method. Background technique [0002] The rotation modulation technology uses the periodic rotation of the index mechanism to eliminate or reduce the navigation error caused by the inertial device, so as to improve the accuracy of the inertial navigation system. Due to its advantages of reducing the accuracy requirements of inertial devices to a certain extent and meeting the system navigation accuracy, it is widely used in high-precision inertial navigation systems. Although the single-axis rotation modulation technology can eliminate or reduce the navigation error caused by the x-axis and y-axis inertial devices through rotation modulation, the error of the z-axis inertial device cannot be eliminated by modulation. Therefore, the inertial device error is st...

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Problems solved by technology

Although system-level calibration can ensure that the calibration accuracy does not depend on the accuracy of the turntable, it must go through the navigation solution process, and use the least square method or filtering algorithm to estimate the inertial device error from the navigation error. The algorithm is cumbersome, and this method can only ensure that the inertial device Calibrate to the same orthogonal coordinate system, although the navigation result is not affected, but because the orthogonal coordinate system calibrated to the inertial device is not the navigation coordinate system, the alignment result deviates greatly from the true value

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