Rotary shaft non-orthogonal angle calibration method of double-shaft rotation inertial navigation system

Abstract

The invention discloses a rotary shaft non-orthogonal angle calibration method of a double-shaft rotation inertial navigation system. The rotary shaft non-orthogonal angle calibration method comprisesthe following steps: 1, establishing a rotary shaft non-orthogonal angle error model of the double-shaft rotation inertial navigation system to obtain a transfer matrix shown in the description of anouter-ring shaft rotation ring rack coordinate system and an inner-ring shaft rotation ring rack coordinate system, and a transfer matrix shown in the description of the inner-ring shaft rotation ring rack coordinate system and an actual IMU (Inertial Measurement Unit) coordinate system; 2, when the double-shaft rotation inertial navigation system has a rotary shaft non-orthogonal angle, solvinga transformation matrix shown in the description from the IMU coordinate system to a navigation coordinate system before double-shaft rotation, and a transformation matrix shown in the description from the IMU coordinate system to the navigation coordinate system after the double-shaft rotation by utilizing the transfer matrix shown in the description and the transfer matrix shown in the description, so as to establish an IMU posture array transformation matrix shown in the description before and after the double-shaft rotation; 3, solving calibration amounts of the rotary shaft non-orthogonalangle of the double-shaft rotation inertial navigation system by utilizing the IMU posture array transformation matrix shown in the description respectively under the conditions of inner-ring shaft rotation and outer-ring shaft rotation. According to the rotary shaft non-orthogonal angle calibration method disclosed by the invention, a rotary shaft non-orthogonal angle error can be calibrated andthe navigation positioning precision of the double-shaft rotation inertial navigation system is improved.

Description

technical field [0001] The invention relates to the technical field of navigation, guidance and control, in particular to a method for calibrating non-orthogonal angles of rotation axes of a dual-axis rotary inertial navigation system. Background technique [0002] The dual-axis rotary inertial navigation system makes the inertial measurement unit periodically roll over through the sequential rotation of the physical inner and outer ring axes, which can effectively modulate the error term of the inertial device. However, no matter what rotation scheme and modulation method is used, although all errors can be modulated theoretically, in practice, due to the uncertainty of the error model, some errors cannot be completely offset by modulation. Therefore, it is still necessary to calibrate the error parameters of the inertial measurement unit (IMU) before the inertial navigation system works, so as to reduce the influence of component errors on navigation accuracy. Since the m...

AI Technical Summary

Problems solved by technology

Since the mechanical arrangement of the dual-axis rotating inertial navigation system is designed under the condition that the model of the dual-axis rotating ring frame is correct, but after the introduction of the dual-axis rotating mechanism, the errors in the rotating mechanism will seriously affect the accuracy of the mechanical arrangement of the inertial navigation system and affect the navigation. precision

Therefore, the inevitable errors of the rotating mechanism will eventually affect the navigation and positioning accuracy. The non-orthogonal angle error between the rotating shafts is the main error of the rotating mechanism. At present, there are few researches on the non-orthogonal calibration between the two-axis rotating shafts. The existing calibration methods generally use traditional nonlinear filter estimation, but the calculation is complicated and the engineering practicability is not strong

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