A Self-Calibration Method of Fiber Optic Gyroscope Scale Factor Based on Ladder Wave Modulation

Abstract

The invention belongs to the field of an inertia sensitive element, and in particular relates to a fiber-optic gyroscope scale factor self-calibration system based on step pulse modulation, which is proposed on the basis of a digital closed-loop fiber-optic gyroscope step pulse modulation principle. The method comprises the following steps: recording a digital quantity of gyro output; respectively calculating and processing data by virtue of an entire-circle calibration process; inputting an angular velocity to corresponding gyro output; generating a Sagnac phase difference in direct proportion to a rotation speed through two light beams differing in transmission direction in an optic fiber loop; adding the calculated digital quantity on a field programmable gate array (FPGA) in Vhsic hardware description language (VHDL); and calculating a gradient by virtue of a least square method. The calibration method disclosed by the invention, not based on a rotary table, can be used for solving the problems that a gyroscope is located in a non-linear area and a calibrated scale factor is not high in precision when the angular velocity inputted by the rotary table in a rotary table calibrating process is too low, and the requirement on the difficulty of the rotary table is increased when the angular velocity is too high; and the calibration method avoids the influence of the precision and the performance of an inertia measurement element on calibration result.

Description

technical field [0001] The invention belongs to the field of inertial sensitive components, and in particular relates to a self-calibration method of the optical fiber gyroscope scale factor based on the step wave modulation proposed by the digital closed-loop optical fiber gyroscope step wave modulation principle. Background technique [0002] The working principle of the strapdown inertial navigation system is to convert its output to the navigation coordinate system through the strapdown matrix, combine certain initial information, and then determine the speed, position and attitude information of the carrier through certain navigation calculations. However, as an autonomous navigation system, the strapdown inertial navigation system will inevitably have some system errors during use. If these errors are not corrected in time, the navigation accuracy of the system will eventually be affected. To compensate these errors, it must first be calibrated with high-precision iner...

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