A Method for Accurately Controlling 2π Voltage Parameters in Closed-loop Fiber Optic Gyro

Abstract

The invention discloses a method for accurately controlling 2Pivoltage parameter in a closed-loop fiber-optic gyroscope. The method includes following steps: 1), respectively sampling light power of light waves reaching a detector in positive-negative modulation half cycles of intrinsic square waves to acquire odd-even sampling values of the fiber-optic gyroscope after modulation of the intrinsic square waves when step waves are not reset and odd-even sampling values of the fiber-optic gyroscope after modulation of the intrinsic square waves when step waves are reset; 2), subtracting the odd-even sampling values during resetting correspondingly by the odd-even sampling values before or after resetting; 3), using DeltaP2Pias a 2Pivoltage adjusting signal to perform servo control on the 2Pivoltage parameter. By the method, whether the step waves are reset or not and whether the 2Pivoltage parameter is accurate or not can be judged accurately so as to accurately adjust the 2Pivoltage parameter of the fiber-optic gyroscope, temperature drift of the fiber-optic gyroscope is reduced, and accuracy of the fiber-optic gyroscope is improved.

Description

technical field [0001] The invention belongs to the field of fiber optic gyroscopes, and in particular relates to a method for precisely controlling 2π voltage parameters in a closed-loop fiber optic gyroscope. Background technique [0002] Closed-loop fiber optic gyroscopes based on digital staircase feedback have been widely used in fiber optic gyroscopes due to their advantages such as high precision, large dynamic range, and good nonlinearity. However, due to the influence of temperature, there are still certain changes in the zero bias and scale factor of the fiber optic gyroscope, and these two parameters are particularly important for the system. Among them, the change of the 2π voltage of the integrated optical modulator (Y waveguide) with the temperature is one of the important reasons for the drift of the two parameters of the fiber optic gyroscope. Therefore, it is of great significance to precisely adjust the 2π voltage parameters in the fiber optic gyroscope to...

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Problems solved by technology

[0008] 2) At a large angular rate, the height of the step is large, and the change range of the step wave is large. If the value of the step wave signal is 124 at a certain moment, if the height of the step is 140, then when the step wave signal rises again, the value of the step wave signal is 124+140 =264, if it exceeds 127, a reset must occur, the value after reset is 264-256=8, the signal before and after reset is positive, the high bit does not change, or the step height is 255, and reset will also occur, and the signal value after reset is 124 +255-256=123, the signal value before and after reset is only one code, that is, the high bits of the signal value before and after reset have not changed, but the ladder wave does reset, which leads to missed judgment;

[0009] 3) Another situation is that when the step wave signal crosses the zero point, that is, the value of the step wave signal changes from negative to positive or positive to negative, and the high level will change. For example: at a certain moment, the value of the step wave signal is -3. If the step height is + 10, then when the ladder wave signal rises again, the value of the ladder wave signal is -3+10=7, which does not exceed 127, and no reset will occur. Misjudgment;

[0010] From the above three situations, it can be seen that judging the change of the high level of the step wave to determine the possibility of missing and misjudging the reset of the step wave, therefore, to explore a new method of judging the reset of the step wave and the method of adjusting the 2π voltage parameters of great significance

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