CN-122015916-A - Fiber optic gyroscope zero bias estimation method based on searching and scoring strategies

CN122015916ACN 122015916 ACN122015916 ACN 122015916ACN-122015916-A

Abstract

The invention discloses a fiber optic gyroscope zero offset estimation method based on a searching and scoring strategy, which comprises the steps of S1, collecting high-precision fiber optic gyroscope original angular rate output data under a quasi-static condition, integrating the gyroscope angular rate output data to obtain a quasi-static period attitude angle sequence, calculating the average value of attitude angles in the quasi-static period attitude angle sequence to obtain an attitude offset sequence, S2, determining a searching space and a searching step length of gyroscope zero offset, S3, generating all candidate zero offset values, correcting the attitude offset sequence to obtain a compensated attitude offset sequence corresponding to each candidate zero offset value, S4, calculating the scoring value of the compensated attitude offset sequence corresponding to each candidate zero offset value, and S5, taking the candidate zero offset value corresponding to the minimum scoring value as the optimal zero offset of a gyroscope based on the scoring value corresponding to each candidate zero offset value obtained in S4. The method can accurately estimate the zero offset of the gyro by high-precision optical fiber inertial navigation.

Inventors

ZHAO QIAN
QIN SHOUPENG
ZHANG YU
LIN YONGWEI
QI CHUNYU
TAN ZHAO
CUI BIN
SHI DEBIN
WANG RAN
NIU YONGXIAO
AN RAN
WANG SHAOLIN

Assignees

中国铁路设计集团有限公司

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (8)

1. A zero offset estimation method of an optical fiber gyroscope based on a searching and scoring strategy is characterized by comprising the following specific steps: s1, acquiring initial angular rate output data of a gyroscope of high-precision optical fiber inertial navigation under a quasi-static condition, integrating the initial angular rate output data of the gyroscope to obtain a quasi-static period attitude angle sequence, calculating the average value of attitude angles in the quasi-static period attitude angle sequence, and further calculating the attitude deviation value of each attitude angle relative to the average value to obtain an attitude deviation sequence; s2, determining a search interval and a search step length of zero offset of the gyroscope; s3, generating all candidate zero offset values in the search interval according to the search step length, and correcting the gesture deviation sequence obtained in S1 based on each candidate zero offset value to form a compensated gesture deviation sequence corresponding to each candidate zero offset value; s4, calculating the grading value of the compensated posture deviation sequence corresponding to each candidate zero deviation value obtained in the step S3; and S5, based on the scoring value corresponding to each candidate zero offset value obtained in the step S4, taking the candidate zero offset value corresponding to the minimum scoring value as the optimal zero offset of the gyroscope.
2. The method for estimating zero offset of an optical fiber gyro according to claim 1, wherein in step S1: The time interval for collecting data is as follows ; The quasi-static time interval attitude angle sequence is , wherein, For the total length of the quasi-static period attitude angle sequence, The attitude angle obtained by time integration is ; The mean value of the attitude angles is , ; Attitude angle Attitude deviation value from mean The method comprises the following steps: , The gesture deviation sequence is 。
3. The method for estimating zero offset of optical fiber gyro according to claim 2, wherein in step S1, the time interval is as follows Consistent with the inertial navigation sampling rate.
4. The method for estimating zero offset of optical fiber gyroscope according to claim 1, wherein in step S2, according to the technical index of the gyroscope used, 5-10 times of the technical index is used as a search interval Taking 1/20-1/10 of the technical index as a search step length 。
5. The method for estimating zero offset of an optical fiber gyroscope according to claim 4, wherein the specific operation in step S3 is as follows: According to the search step length Generating the search interval All candidate zero offset values in the same Record the number of The candidate zero offset value is , wherein, ; Based on candidate zero offset values Correcting the attitude deviation sequence obtained in the step S1 Each attitude deviation value in the model (C) is obtained and is matched with each candidate zero deviation value Corresponding compensated attitude deviation sequences: , Wherein, the Attitude deviation value after time compensation 。
6. The method for estimating zero offset of optical fiber gyroscope according to claim 5, wherein the specific operation in step S4 is that the absolute value of each attitude deviation value in the compensated attitude deviation sequence is obtained Then, the absolute value gesture deviation sequence is formed by ascending order, based on the prior knowledge, a percentage threshold value is set Before selecting the absolute value attitude deviation sequence The average value is calculated as the current candidate zero offset value Score value of (2) is recorded as Obtaining a scoring sequence 。
7. The method of zero offset estimation of a fiber optic gyroscope of claim 6, wherein in step S4, the percentage threshold is Representing the proportion of data with no or little interference, and adjusting the proportion within the range of 70% -90%.
8. The method for estimating zero offset of an optical fiber gyroscope according to claim 6, wherein the specific operation in step S5 is as follows: Obtaining a scoring value sequence based on S4 Finding the minimum value in the scoring values , The corresponding candidate zero offset value is the optimal zero offset value of the gyroscope 。

Description

Fiber optic gyroscope zero bias estimation method based on searching and scoring strategies Technical Field The invention relates to the technical field of rail transit precise measurement, in particular to a zero offset estimation method of an optical fiber gyroscope based on a searching and scoring strategy. Background When the high-precision optical fiber inertial navigation is subjected to initial alignment or zero offset alignment under static or quasi-static conditions, the attitude angle of the inertial navigation is obtained by integrating the output angular rate of the gyroscope. In this process, the main error sources of the gyroscopes are zero bias and angle random walk. In an ideal state, the attitude angle of the static base is a constant value, and the attitude change after integration is mainly caused by zero offset, so that the zero offset of the gyroscope can be estimated by a method of linear fitting of an attitude sequence and the like. However, in practical applications (e.g., inertial navigation is mounted on a railroad rail detection platform), the equipment is not at absolute rest. The operator touches the equipment, the operation screen, the automatic rotation of the total station, wind blowing, mechanical vibration and other environmental factors, and random, irregular, short-time and unstable-amplitude gesture disturbance can be caused. As shown in fig. 1, these disturbances result in non-zero-bias-induced "abrupt" or "drift" in the pose sequence, and the timing, amplitude, and duration of the occurrence are all irregularly circulated. If the linear fitting or the average processing is directly performed on the full-time-period attitude data, the interference data can seriously pollute the zero offset estimation result, so that the estimated value deviates from the true zero offset, and further the subsequent navigation precision is affected. Conventional methods typically detect and reject data of the interference period by setting thresholds (e.g., angular velocity threshold, attitude change rate threshold). However, this method has the following significant drawbacks: 1) The threshold is difficult to set adaptively, too tightly will lose valid data, too wide, interference cannot be filtered; 2) The detection effect on irregular and non-pulse slow disturbance (such as slow inclination caused by long-time pressing) is poor; 3) The robustness of the method depends on scene and empirical tuning. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a fiber optic gyroscope zero offset estimation method based on a searching and scoring strategy, which is used for accurately estimating the zero offset of a high-precision fiber optic inertial navigation gyroscope. For this purpose, the invention adopts the following technical scheme: a zero offset estimation method of an optical fiber gyroscope based on a searching and scoring strategy comprises the following specific steps: s1, acquiring initial angular rate output data of a gyroscope of high-precision optical fiber inertial navigation under a quasi-static condition, integrating the initial angular rate output data of the gyroscope to obtain a quasi-static period attitude angle sequence, calculating the average value of attitude angles in the quasi-static period attitude angle sequence, and further calculating the attitude deviation value of each attitude angle relative to the average value to obtain an attitude deviation sequence; s2, determining a search interval and a search step length of zero offset of the gyroscope; s3, generating all candidate zero offset values in the search interval according to the search step length, and correcting the gesture deviation sequence obtained in S1 based on each candidate zero offset value to form a compensated gesture deviation sequence corresponding to each candidate zero offset value; s4, calculating the grading value of the compensated posture deviation sequence corresponding to each candidate zero deviation value obtained in the step S3; and S5, based on the scoring value corresponding to each candidate zero offset value obtained in the step S4, taking the candidate zero offset value corresponding to the minimum scoring value as the optimal zero offset of the gyroscope. In the step S1, the following steps are performed: The time interval for collecting data is as follows ; The quasi-static time interval attitude angle sequence is, wherein,For the total length of the quasi-static period attitude angle sequence,The attitude angle obtained by time integration is; The mean value of the attitude angles is,; Attitude angleAttitude deviation value from meanThe method comprises the following steps: , The gesture deviation sequence is 。 In the step S1, the time intervalConsistent with the inertial navigation sampling rate. In the step S2, according to the technical index of the gyroscope, 5-10 times of the technical index is used as a search intervalTaking 1/