Method for calibrating optical strapdown inertial navigation system based on two-axis turntable

Abstract

The utility model relates to a method for calibrating an optical strapdown inertial navigation system based on a two-axis turntable. The method comprises the following six steps: firstly, selecting an error model; secondly, mounting three axles of the optical strapdown inertial navigation system to the two-axis turntable according to the east-north-up direction, and then collecting data after the whole system is powered on and preheated; thirdly, collecting data and storing the data to a calibration matrix according to the twelve positions of east-north-up, west-south-up, north-east-down, south-west-down, up-south-east, up-north-west, down-north-east, down-south-west, south-up-west, north-up-east, south-down-east and north-down-west; fourthly, rotating around the z-axis, the y-axis or the x-axis for 3 minutes at omega of plus or minus 2 degrees per seconds, plus or minus 10 degrees per seconds, plus or minus 30 degrees per seconds, plus or minus 60 degrees per seconds or plus or minus 100 degrees per seconds according to the two positions of east-north-up and north-west-up, and equalizing the output data and storing the average value in the calibration matrix; fifthly, collecting data for 15 minutes at each position of the four positions of east-north-up, west-north-up, north-east-down and south-west-down, and then equalizing the output data and storing the average value in the calibration matrix; and sixthly, using the least square method for calculating the calibration parameters of an accelerometer, and using an analysis method for calculating the calibration parameters of a gyroscope.

Description

(1) Technical field [0001] The invention relates to a calibration method of an optical strapdown inertial navigation system based on a double-axis turntable, and belongs to the technical field of calibration and detection of aviation and aerospace navigation instruments. (2) Background technology [0002] Calibration technology is essentially an error compensation technology. The so-called calibration is to establish the model equation of the inertial instrument and the inertial system, use special test equipment and software algorithms to calibrate the error items of the instrument and the system, and give compensation to improve the actual use accuracy of the instrument and system. The current calibration method needs to use the turntable to perform a pre-set calibration path, and through the position measurement test and the speed measurement test, the zero offset value, scale factor, and installation error of the optical gyroscope are calibrated; the zero offset value of...

AI Technical Summary

Problems solved by technology

[0012] 1) Based on the calibration method of the three-axis turntable, it is difficult to eliminate the influence of the error of the turntable itself, which in turn affects the calibration accuracy;

[0013] 2) The three-axis turntable has disadvantages such as high price, large volume, and difficult installation and maintenance;

[0014] 3) Judging from the existing literature, there is currently no calibration method based on the design of a two-axis turntable that takes into account its rotation function and accuracy requirements

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