A calibration method for installation attitude of strapdown inertial navigation system for photoelectric tracking system

Abstract

The invention discloses a method for calibrating the installation attitude of a strapdown inertial navigation system for a photoelectric tracking system, comprising: establishing coordinate systems n, b, t, and s; initial alignment of the strapdown inertial navigation multiple times and taking the average value to obtain a shortcut The initial attitude Euler angle of the joint inertial navigation; place the theodolite with azimuth reference in each measurement position in turn, complete the alignment, record the azimuth and elevation angle of the theodolite with azimuth reference and the azimuth and elevation angle of the photoelectric tracking system, and seek north for many times. Record the average value of the north-seeking results, and calculate the difference of the vertical plate index; establish a unit vector parallel to the visual axis of the photoelectric tracking system, the starting point is the origin of the coordinate system, and calculate the attitude matrix from the t system to the s system based on the coordinates in the s system. The coordinate calculation in the t system is based on the Euler angle, the calculation of the attitude matrix from the n system to the b system and the calculation of the coordinates in the b system are based on k linear equations combined with the establishment of linear equations to solve the present invention. Can be used for indoor calibration.

Description

technical field [0001] The invention relates to the field of photoelectric tracking system testing, in particular to a method for calibrating the installation attitude of a strapdown inertial navigation system for a photoelectric tracking system. Background technique [0002] The field of view of the photoelectric tracking system is usually several orders of magnitude, and it is difficult to directly capture the target. Before tracking the target, external information is required for guidance, such as radar or GPS information. Usually the external guidance information can be converted to spherical coordinates in the geographic coordinate system. In order to obtain the attitude of the carrier platform of the photoelectric tracking system relative to the geographic coordinate system, the inertial navigation system is installed on the carrier platform of the photoelectric tracking system and strapped down to the base. Inertial navigation measures the attitude of the carrier pla...

AI Technical Summary

Problems solved by technology

[0007] The above methods have some disadvantages. The first method is guaranteed by the mechanism, which has high requirements for structural design, processing and assembly, high cost, and requires multiple mechanical reference conversions, and the error is not easy to guarantee.

Both method 2 and method 3 need to be carried out in the field. First, a relatively open field is required. Among them, method 3 needs to fly a drone, which has more constraints on the field; Especially large photoelectric tracking system

In method 2, it is troublesome to measure the benchmark under the geographic system, and in method 3, there is a very high requirement for time synchronization accuracy, which is not easy to guarantee

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